Commit Graph

4869 Commits

Author SHA1 Message Date
Fabio Estevam
5ac88295fc serial: imx: Remove unused members from imx_port struct
IRDA support is gone since commit afe9cbb1a6 ("serial: imx: drop
support for IRDA"), so remove the remaining irda members from
imx_port structure.

While at it, also remove 'trcv_delay' which is also unused.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 17:08:01 +02:00
Vignesh R
a1bfb6eb30 serial: 8250: 8250_omap: Fix race b/w dma completion and RX timeout
DMA RX completion handler for UART is called from a tasklet and hence
may be delayed depending on the system load. In meanwhile, there may be
RX timeout interrupt which can get serviced first before DMA RX
completion handler is executed for the completed transfer.
omap_8250_rx_dma_flush() which is called on RX timeout interrupt makes
sure that the DMA RX buffer is pushed and then the FIFO is drained and
also queues a new DMA request. But, when DMA RX completion handler
executes, it will erroneously flush the currently queued DMA transfer
which sometimes results in data corruption and double queueing of DMA RX
requests.

Fix this by checking whether RX completion is for the currently queued
transfer or not. And also hold port lock when in DMA completion to avoid
race wrt RX timeout handler preempting it.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 17:03:10 +02:00
Phil Elwell
cfde770d94 serial: 8250: Fix THRE flag usage for CAP_MINI
The BCM2835 MINI UART has non-standard THRE semantics. Conventionally
the bit means that the FIFO is empty (although there may still be a
byte in the transmit register), but on 2835 it indicates that the FIFO
is not full. This causes interrupts after every byte is transmitted,
with the FIFO providing some interrupt latency tolerance.

A consequence of this difference is that the usual strategy of writing
multiple bytes into the TX FIFO after checking THRE once is unsafe.
In the worst case of 7 bytes in the FIFO, writing 8 bytes loses all
but the first since by then the FIFO is full.

There is an HFIFO ("Hidden FIFO") capability that causes the transmit
loop to terminate when both THRE and TEMT are set, i.e. when the TX
block is completely idle. This is unnecessarily cautious, potentially
causing gaps in transmission.

Add a new conditional to the transmit loop, predicated on CAP_MINI,
that exits when THRE is no longer set (the FIFO is full). This allows
the FIFO to fill quickly but subsequent writes are paced by the
transmission rate.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 17:03:10 +02:00
Okash Khawaja
fc61ed5127 tty: add function to convert device name to number
The function converts strings like ttyS0 and ttyUSB0 to dev_t like
(4, 64) and (188, 0). It does this by scanning tty_drivers list for
corresponding device name and index. If the driver is not registered,
this function returns -ENODEV. It also acquires tty_mutex.

Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-27 09:08:47 +02:00
Ingo Molnar
ac6424b981 sched/wait: Rename wait_queue_t => wait_queue_entry_t
Rename:

	wait_queue_t		=>	wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:18:27 +02:00
Jan Kiszka
d3936d7437 gpio-exar/8250-exar: Fix passing in of parent PCI device
This fixes reloading of the GPIO driver for the same platform device
instance as created by the exar UART driver: First of all, the driver
sets drvdata to its own value during probing and does not restore the
original value on exit. But this won't help anyway as the core clears
drvdata after the driver left.

Set the platform device parent instead.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-20 10:12:39 +02:00
Helmut Klein
9f60e0e7ae tty/serial: meson_uart: update to stable bindings
This patch handle the stable UART bindings but also keeps compatibility
with the legacy non-stable bindings until all boards uses them.

Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Helmut Klein <hgkr.klein@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20 10:46:27 +08:00
Matthias Brugger
1104321a7b serial: Delete dead code for CIR serial ports
Commit e4fda3a042 ("serial: don't register CIR serial ports") adds a
check for PORT_8250_CIR to serial8250_register_8250_port(). But the code
isn't needed as the function never takes the branch when the port is CIR
serial port.

This patch deletes the dead code.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20 10:24:15 +08:00
Arvind Yadav
519495431d serial: sirf: make of_device_ids const
of_device_ids are not supposed to change at runtime. All functions
working with of_device_ids provided by <linux/of.h> work with const
of_device_ids. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20 10:24:15 +08:00
Christoph Hellwig
7b45fff006 serial/mpsc: switch to dma_alloc_attrs
Use dma_alloc_attrs directly instead of the dma_alloc_noncoherent wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20 10:24:15 +08:00
Andreas Färber
e36361d70e tty: serial: Add Actions Semi Owl UART earlycon
This implements an earlycon for Actions Semi S500/S900 SoCs.

Based on LeMaker linux-actions tree.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20 10:24:15 +08:00
Johannes Berg
59ae1d127a networking: introduce and use skb_put_data()
A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 11:48:37 -04:00
Alexandre Belloni
92c8f7c0e1 tty/serial: atmel: make the driver DT only
Now that AVR32 is gone, platform_data are not used to initialize the driver
anymore, remove that path from the driver. Also remove the now unused
struct atmel_uart_data.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14 12:48:48 +02:00
Alexandre Belloni
274a5ed6d8 tty/serial: atmel: remove atmel_default_console_device handling
atmel_default_console_device was only used by AVR32, in particular
arch/avr32/mach-at32ap/at32ap700x.c which is now gone. Remove it from the
driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14 12:48:48 +02:00
Johan Hovold
48a7bd1178 tty: rocket: drop broken alt-speed support
Setting an alt_speed using the ROCKET_SPD flags has been deprecated
since v2.1.69, and has been broken since commit 6865ff222c ("TTY: do
not warn about setting speed via SPD_*") without anyone noticing.

To make things worse commit 6df3526b66 ("rocket: first pass at termios
reporting") in v2.6.25 started reporting back the actual baud rate used,
something which also required 38400 to again be set whenever changing a
SPD flag.

Drop the broken alt-speed handling altogether, and add a ratelimited
warning about using TIOCCSERIAL to change speed as being deprecated.

Note that the rocket driver has never supported using a custom divisor
(ASYNC_SPD_CUST equivalent).

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:49:58 +02:00
Johan Hovold
d1b8bc3bc2 tty: cyclades: drop broken alt-speed support
Setting an alt_speed using the ASYNC_SPD flags has been deprecated since
v2.1.69, and has been broken since v3.10 and commit 6865ff222c ("TTY:
do not warn about setting speed via SPD_*") without anyone noticing.

Drop the broken alt-speed handling altogether, and add a ratelimited
warning about using TIOCCSERIAL to to change speed as being deprecated.

Note that using ASYNC_SPD_CUST is still supported.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:49:58 +02:00
Johan Hovold
6086380a55 tty: amiserial: drop broken alt-speed support
Setting an alt_speed using the ASYNC_SPD flags has been deprecated since
v2.1.69, and has been broken since v3.10 and commit 6865ff222c ("TTY:
do not warn about setting speed via SPD_*") without anyone noticing.

Drop the broken alt-speed handling altogether, and add a ratelimited
warning about using TIOCCSERIAL to change speed as being deprecated.

Note that using ASYNC_SPD_CUST is still supported.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:49:58 +02:00
Johan Hovold
dc2f727159 serial: rate limit custom-speed deprecation notice
Contrary to what a comment claimed, the ASYNC_SPD flags and custom
divisor can be set by a non-privileged user so rate limit the
deprecation notice as was intended.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:49:57 +02:00
Heiko Carstens
20d58cb642 s390/hvc_iucv: fix broken Kconfig select statement
Select statements in Kconfig do not necessarily enable all required
dependencies and can lead to broken configs. This is also the case
for the "select IUCV" statement within HVC_IUCV:

warning: (HVC_IUCV) selects IUCV which has unmet direct
         dependencies (NET && S390)

Just add the missing "depends on NET" to avoid broken configs.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-06-12 16:25:58 +02:00
Greg Kroah-Hartman
4e70a6fe6d TTY: hvc: convert to use DRIVER_ATTR_RW
We are trying to get rid of DRIVER_ATTR(), and the hvc driver's
attribute can be trivially changed to use DRIVER_ATTR_RW().

Cc: Jiri Slaby <jslaby@suse.com>
Cc: <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-12 16:14:30 +02:00
Greg Kroah-Hartman
7bf1e44f86 Merge 4.12-rc5 into staging-next
We want the IIO fixes and other staging driver fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-12 08:20:47 +02:00
Aleksa Sarai
54ebbfb160 tty: add TIOCGPTPEER ioctl
When opening the slave end of a PTY, it is not possible for userspace to
safely ensure that /dev/pts/$num is actually a slave (in cases where the
mount namespace in which devpts was mounted is controlled by an
untrusted process). In addition, there are several unresolvable
race conditions if userspace were to attempt to detect attacks through
stat(2) and other similar methods [in addition it is not clear how
userspace could detect attacks involving FUSE].

Resolve this by providing an interface for userpace to safely open the
"peer" end of a PTY file descriptor by using the dentry cached by
devpts. Since it is not possible to have an open master PTY without
having its slave exposed in /dev/pts this interface is safe. This
interface currently does not provide a way to get the master pty (since
it is not clear whether such an interface is safe or even useful).

Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Valentin Rothberg <vrothberg@suse.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 12:27:54 +02:00
Aleksa Sarai
5f0f187fd0 tty: add compat_ioctl callbacks
In order to avoid future diversions between fs/compat_ioctl.c and
drivers/tty/pty.c, define .compat_ioctl callbacks for the relevant
tty_operations structs. Since both pty_unix98_ioctl() and
pty_bsd_ioctl() are compatible between 32-bit and 64-bit userspace no
special translation is required.

Signed-off-by: Aleksa Sarai <asarai@suse.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:27:20 +02:00
Jan Kiszka
bea8be6561 serial: exar: Leave MPIOs as output for Commtech adapters
Commtech adapters apparently need the original setting as outputs, see
https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that.

Fixes: 7dea8165f1 ("serial: exar: Preconfigure xr17v35x MPIOs as output")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:23:36 +02:00
Andy Shevchenko
72ce5732ee tty/serial: atmel: Remove AVR32 bits from the driver
AVR32 is gone. Now it's time to clean up the driver by removing
leftovers that was used by AVR32 related code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:22:14 +02:00
Adam Borowski
1c65a879cc vt: fix \e[2m using the wrong placeholder color on graphical consoles
Only vgacon and sisusbcon did it right, the rest (via generic code) tried
underline (usually cyan).

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:20:08 +02:00
Greg Kroah-Hartman
e0ac3f9825 Merge branch 'vt_copy_cleanup' into tty-next
The vt copy_from/to_user cleanups were in a separate branch for others
to work off of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:19:02 +02:00
Adam Borowski
f8564c93e0 vt: drop access_ok() calls in unimap ioctls
Done by copy_{from,to}_user().

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:07:36 +02:00
Adam Borowski
4f1be1b5d9 vt: use memdup_user in PIO_UNIMAP ioctl
Again, a nice linear transfer that simplifies the code.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:07:36 +02:00
Adam Borowski
915f0a8d28 vt: use copy_to_user instead of __put_user in GIO_UNIMAP ioctl
A nice big linear transfer, no need to flip stac/PAN/etc every half-entry.
Also, yay __put_user() after checking only read.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:07:36 +02:00
Adam Borowski
6987dc8a70 vt: fix unchecked __put_user() in tioclinux ioctls
Only read access is checked before this call.

Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.

If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
CC: stable@vger.kernel.org # v3.7-
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:07:36 +02:00
Adam Borowski
cc1e66f92b vt: use copy_from/to_user instead of __get/put_user for scrnmap ioctls
Linus wants to get rid of these functions, and these uses are especially
egregious: they copy a big linear array element by element.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:07:36 +02:00
Greg Kroah-Hartman
4fe99816a1 tty: serdev: use dev_groups and not dev_attrs for bus_type
The dev_attrs field has long been "depreciated" and is finally being
removed, so move the driver to use the "correct" dev_groups field
instead for struct bus_type.

Cc: Rob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:00:46 +02:00
Greg Kroah-Hartman
8bc39bca5e Merge 4.12-rc4 into tty-next
We want the tty locking fix in here, so that maybe we can finally get it
fixed for real...

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-05 09:27:05 +02:00
Greg Kroah-Hartman
fc098af16b Revert "tty: fix port buffer locking"
This reverts commit 925bb1ce47.

It causes lots of warnings and problems so for now, let's just revert
it.

Reported-by: <valdis.kletnieks@vt.edu>
Reported-by: Russell King <linux@armlinux.org.uk>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-04 10:23:25 +02:00
Nava kishore Manne
094094a937 serial: uartps: Fix kernel doc warnings
This patch fixes the kernel doc warnings in the driver.

Signed-off-by: Nava kishore Manne <navam@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:48:53 +09:00
Joel Stanley
e2860e1f62 serial: 8250_of: Add reset support
This adds the hooks for an optional reset controller in the 8250 device
tree node.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:48:52 +09:00
Sascha Hauer
71e0779153 tty: n_gsm: do not send/receive in ldisc close path
gsm_cleanup_mux() is called in the line discipline close path which
is called at tty_release() time. At this stage the tty is no longer
operational enough to send any frames. Sending close frames is
therefore not possible and waiting for their answers always times
out.

This patch removes sending close messages and waiting for their answers
from the tty_release path.

This patch makes explicit what previously implicitly had been the case
already: We are not able to tell the modem that we are about to close
the multiplexer on our side. This means the modem will stay in
multiplexer mode and re-establishing the multiplexer later fails. The
only way for userspace to work around this is to manually send a close
frame in N_TTY mode after closing the mux.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:48:52 +09:00
Thomas Bogendoerfer
e279e6d98e Fix serial console on SNI RM400 machines
sccnxp driver doesn't get the correct uart clock rate, if CONFIG_HAVE_CLOCK
is disabled. Correct usage of clk API to make it work with/without it.

Fixes: 90efa75f7a (serial: sccnxp: Using CLK API for getting UART clock)

Suggested-by: Russell King - ARM Linux <linux@armlinux.org.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:48:52 +09:00
Alan Cox
8a8dabf2dd tty: handle the case where we cannot restore a line discipline
Historically the N_TTY driver could never fail but this has become broken over
time. Rather than trying to rewrite half the ldisc layer to fix the breakage
introduce a second level of fallback with an N_NULL ldisc which cannot fail,
and thus restore the guarantees required by the ldisc layer.

We still try and fail to N_TTY first. It's much more useful to find yourself
back in your old ldisc (first attempt) or in N_TTY (second attempt), and while
I'm not aware of any code out there that makes those assumptions it's good to
drive(r) defensively.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:43:46 +09:00
Greg Kroah-Hartman
aa668632ae Merge 4.12-rc3 into tty-next
We need the tty fixes/changes here to handle future work.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-29 08:18:15 +02:00
Tobias Klauser
59fe2cc8b1 serial: altera_uart: call iounmap() at driver remove
The driver calls ioremap() in the probe function but doesn't call
iounmap() in the remove function correspondingly. Do so now.

Follow commit 5c9d6abed9 ("serial: altera_jtaguart: adding iounmap()")

Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 14:36:37 +02:00
Uwe Kleine-König
6df765dca3 serial: imx: ensure UCR3 and UFCR are setup correctly
Commit e61c38d85b ("serial: imx: setup DCEDTE early and ensure DCD and
RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using
read-modify-write before it switched to write register values
independent of the previous state. That's a good idea in principle (and
that's why I did it) but needs more care.

This patch reinstates read-modify-write for UFCR and for UCR3 ensures
that RXDMUXSEL and ADNIMP are set for post imx1.

Fixes: e61c38d85b ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Mika Penttilä <mika.penttila@nextfour.com>
Tested-by: Mika Penttilä <mika.penttila@nextfour.com>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Tested-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 14:35:53 +02:00
Phil Elwell
d087e7a991 serial: 8250: Add CAP_MINI, set for bcm2835aux
The AUX/mini-UART in the BCM2835 family of procesors is a cut-down
8250 clone. In particular it is lacking support for the following
features: CSTOPB PARENB PARODD CMSPAR CS5 CS6

Add a new capability (UART_CAP_MINI) that exposes the restrictions to
the user of the termios API by turning off the unsupported features in
the request.

N.B. It is almost possible to automatically discover the missing
features by reading back the LCR register, but the CSIZE bits don't
cooperate (contrary to the documentation, both bits are significant,
but CS5 and CS6 are mapped to CS7) and the code is much longer.

See: https://github.com/raspberrypi/linux/issues/1561

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-24 15:15:56 +02:00
Geert Uytterhoeven
9b7becf103 serial: sh-sci: Update warning message in sci_request_dma_chan()
The commit below changed a function call from
dma_request_slave_channel_compat() to dma_request_slave_channel(), but
forgot to update the printed failure message.

Fixes: 219fb0c143 ("serial: sh-sci: Remove the platform data dma slave rx/tx channel IDs")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-24 15:15:56 +02:00
Arnd Bergmann
5fa4accf5e serial: meson: hide an unused function
The newly added meson_uart_enable_tx_engine function is only called
from the console setup, not the runtime uart, which has an open-coded
version of the same register access. This produces a harmless warning
when the console code is disabled:

drivers/tty/serial/meson_uart.c:127:13: error: 'meson_uart_enable_tx_engine' defined but not used [-Werror=unused-function]

Let's move the function inside of the #ifdef to avoid the warning.

Fixes: ba50f1df13 ("serial: meson: remove unneeded variable assignment in meson_serial_port_write")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-24 15:15:56 +02:00
Johan Hovold
da4c279942 serial: enable serdev support
Enable serdev support by using the new device-registration helpers.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 17:38:25 +02:00
Johan Hovold
8cde11b2ba tty/serdev: add serdev registration interface
Add a new interface for registering a serdev controller and clients, and
a helper function to deregister serdev devices (or a tty device) that
were previously registered using the new interface.

Once every driver currently using the tty_port_register_device() helpers
have been vetted and converted to use the new serdev registration
interface (at least for deregistration), we can move serdev registration
to the current helpers and get rid of the serdev-specific functions.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 17:38:24 +02:00
Stefan Wahren
6bdc00d01e serdev: Restore serdev_device_write_buf for atomic context
Starting with commit 6fe729c4bd ("serdev: Add serdev_device_write
subroutine") the function serdev_device_write_buf cannot be used in
atomic context anymore (mutex_lock is sleeping). So restore the old
behavior.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: 6fe729c4bd ("serdev: Add serdev_device_write subroutine")
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:45:53 +02:00
Lucas Stach
88e2582e90 serial: core: fix crash in uart_suspend_port
With serdev we might end up with serial ports that have no cdev exported
to userspace, as they are used as the bus interface to other devices. In
that case serial_match_port() won't be able to find a matching tty_dev.

Skip the irq wakeup enabling in that case, as serdev will make sure to
keep the port active, as long as there are devices depending on it.

Fixes: 8ee3fde047 (tty_port: register tty ports with serdev bus)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Vegard Nossum
925bb1ce47 tty: fix port buffer locking
tty_insert_flip_string_fixed_flag() is racy against itself when called
from the ioctl(TCXONC, TCION/TCIOFF) path [1] and the flush_to_ldisc()
workqueue path [2].

The problem is that port->buf.tail->used is modified without consistent
locking; the ioctl path takes tty->atomic_write_lock, whereas the workqueue
path takes ldata->output_lock.

We cannot simply take ldata->output_lock, since that is specific to the
N_TTY line discipline.

It might seem natural to try to take port->buf.lock inside
tty_insert_flip_string_fixed_flag() and friends (where port->buf is
actually used/modified), but this creates problems for flush_to_ldisc()
which takes it before grabbing tty->ldisc_sem, o_tty->termios_rwsem,
and ldata->output_lock.

Therefore, the simplest solution for now seems to be to take
tty->atomic_write_lock inside tty_port_default_receive_buf(). This lock
is also used in the write path [3] with a consistent ordering.

[1]: Call Trace:
 tty_insert_flip_string_fixed_flag
 pty_write
 tty_send_xchar                     // down_read(&o_tty->termios_rwsem)
                                    // mutex_lock(&tty->atomic_write_lock)
 n_tty_ioctl_helper
 n_tty_ioctl
 tty_ioctl                          // down_read(&tty->ldisc_sem)
 do_vfs_ioctl
 SyS_ioctl

[2]: Workqueue: events_unbound flush_to_ldisc
Call Trace:
 tty_insert_flip_string_fixed_flag
 pty_write
 tty_put_char
 __process_echoes
 commit_echoes                      // mutex_lock(&ldata->output_lock)
 n_tty_receive_buf_common
 n_tty_receive_buf2
 tty_ldisc_receive_buf              // down_read(&o_tty->termios_rwsem)
 tty_port_default_receive_buf       // down_read(&tty->ldisc_sem)
 flush_to_ldisc                     // mutex_lock(&port->buf.lock)
 process_one_work

[3]: Call Trace:
 tty_insert_flip_string_fixed_flag
 pty_write
 n_tty_write                        // mutex_lock(&ldata->output_lock)
                                    // down_read(&tty->termios_rwsem)
 do_tty_write (inline)              // mutex_lock(&tty->atomic_write_lock)
 tty_write                          // down_read(&tty->ldisc_sem)
 __vfs_write
 vfs_write
 SyS_write

The bug can result in about a dozen different crashes depending on what
exactly gets corrupted when port->buf.tail->used points outside the
buffer.

The patch passes my LOCKDEP/PROVE_LOCKING testing but more testing is
always welcome.

Found using syzkaller.

Cc: <stable@vger.kernel.org>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Johan Hovold
11d4d32158 tty: ehv_bytechan: clean up init error handling
Straighten out the initcall error handling to avoid deregistering a
never-registered tty driver (something which would lead to a
NULL-pointer dereference) in the most unlikely event that driver
registration fails (e.g. we've run out of major numbers).

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Johan Hovold
1e948479b3 serial: ifx6x60: fix use-after-free on module unload
Make sure to deregister the SPI driver before releasing the tty driver
to avoid use-after-free in the SPI remove callback where the tty
devices are deregistered.

Fixes: 72d4724ea5 ("serial: ifx6x60: Add modem power off function in the platform reboot process")
Cc: stable <stable@vger.kernel.org>     # 3.8
Cc: Jun Chen <jun.d.chen@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Alexey Khoroshilov
5c9d6abed9 serial: altera_jtaguart: adding iounmap()
The driver does ioremap(port->mapbase, ALTERA_JTAGUART_SIZE),
but there is no any iounmap().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Jan Kiszka
2c0ac5b48a serial: exar: Fix stuck MSIs
After migrating 8250_exar to MSI in 172c33cb61, we can get stuck
without further interrupts because of the special wake-up event these
chips send. They are only cleared by reading INT0. As we fail to do so
during startup and shutdown, we can leave the interrupt line asserted,
which is fatal with edge-triggered MSIs.

Add the required reading of INT0 to startup and shutdown. Also account
for the fact that a pending wake-up interrupt means we have to return 1
from exar_handle_irq. Drop the unneeded reading of INT1..3 along with
this - those never reset anything.

An alternative approach would have been disabling the wake-up interrupt.
Unfortunately, this feature (REGB[17] = 1) is not available on the
XR17D15X.

Fixes: 172c33cb61 ("serial: exar: Enable MSI support")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Christophe JAILLET
be40597a1b serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'
UARTn_FRAME_PARITY_ODD is 0x0300
UARTn_FRAME_PARITY_EVEN is 0x0200
So if the UART is configured for EVEN parity, it would be reported as ODD.
Fix it by correctly testing if the 2 bits are set.

Fixes: 3afbd89c96 ("serial/efm32: add new driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:43:55 +02:00
Johan Hovold
aee5da7838 serdev: fix tty-port client deregistration
The port client data must be set when registering the serdev controller
or client deregistration will fail (and the serdev devices are left
registered and allocated) if the port was never opened in between.

Make sure to clear the port client data on any probe errors to avoid a
use-after-free when the client is later deregistered unconditionally
(e.g. in a tty-port deregistration helper).

Also move port client operation initialisation to registration. Note
that the client ops must be restored on failed probe.

Fixes: bed35c6dfa ("serdev: add a tty port controller driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:41:49 +02:00
Johan Hovold
d3ba126a22 Revert "tty_port: register tty ports with serdev bus"
This reverts commit 8ee3fde047.

The new serdev bus hooked into the tty layer in
tty_port_register_device() by registering a serdev controller instead of
a tty device whenever a serdev client is present, and by deregistering
the controller in the tty-port destructor. This is broken in several
ways:

Firstly, it leads to a NULL-pointer dereference whenever a tty driver
later deregisters its devices as no corresponding character device will
exist.

Secondly, far from every tty driver uses tty-port refcounting (e.g.
serial core) so the serdev devices might never be deregistered or
deallocated.

Thirdly, deregistering at tty-port destruction is too late as the
underlying device and structures may be long gone by then. A port is not
released before an open tty device is closed, something which a
registered serdev client can prevent from ever happening. A driver
callback while the device is gone typically also leads to crashes.

Many tty drivers even keep their ports around until the driver is
unloaded (e.g. serial core), something which even if a late callback
never happens, leads to leaks if a device is unbound from its driver and
is later rebound.

The right solution here is to add a new tty_port_unregister_device()
helper and to never call tty_device_unregister() whenever the port has
been claimed by serdev, but since this requires modifying just about
every tty driver (and multiple subsystems) it will need to be done
incrementally.

Reverting the offending patch is the first step in fixing the broken
lifetime assumptions. A follow-up patch will add a new pair of
tty-device registration helpers, which a vetted tty driver can use to
support serdev (initially serial core). When every tty driver uses the
serdev helpers (at least for deregistration), we can add serdev
registration to tty_port_register_device() again.

Note that this also fixes another issue with serdev, which currently
allocates and registers a serdev controller for every tty device
registered using tty_port_device_register() only to immediately
deregister and deallocate it when the corresponding OF node or serdev
child node is missing. This should be addressed before enabling serdev
for hot-pluggable buses.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:41:49 +02:00
Ard Biesheuvel
4c4fc90964 drivers/tty: 8250: only call fintek_8250_probe when doing port I/O
Commit fa01e2ca9f ("serial: 8250: Integrate Fintek into 8250_base")
modified the probing logic for PNP0501 devices, to remove a collision
between the generic 16550A driver and the Fintek driver, which reused
the same ACPI _HID.

The Fintek device probe is now incorporated into the common 8250 probe
path, and gets called for all discovered 16550A compatible devices,
including ones that are MMIO mapped rather than IO mapped. However,
the Fintek driver assumes the port base is a I/O address, and proceeds
to probe some arbitrary offsets above it.

This is generally a wrong thing to do, but on ARM systems (having no
native port I/O), this may result in faulting accesses of completely
unrelated MMIO regions in the PCI I/O space. Given that this is at
serial probe time, this results in hard to diagnose crashes at boot.

So let's restrict the Fintek probe to devices that we know are using
port I/O in the first place.

Fixes: fa01e2ca9f ("serial: 8250: Integrate Fintek into 8250_base")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ricardo Ribalda <ricardo.ribalda@gmail.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:39:10 +02:00
Shubhrajyoti Datta
d653c43aef serial: xilinx_uartps: Fix the error path
Fix the runtime calls in the error path.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:38:20 +02:00
Heiner Kallweit
8b7a6b2b8e serial: meson: change interrupt description to tty name
Change interrupt description from driver name to tty name
(e.g. ttyAML0). If multiple serial ports are enabled this
allows to determine which interrupt belongs to which port
in /proc/interrupts.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:37:27 +02:00
Heiner Kallweit
1b1ecaa69c serial: meson: remove use of flag UPF_IOREMAP
Flag UPF_IOREMAP is used by the 8250 subsystem only, it's not used
by the serial core. Therefore I don't see any benefit in using it
here.

In addition fix the order of calls in meson_uart_release_port.
Unmapping needs to be done first, reversing call order in
meson_uart_request_port.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:36:13 +02:00
Heiner Kallweit
ff3b9cad7d serial: meson: make use of uart_port member mapsize
Member mapsize of struct uart_port is meant to store the resource size.
By using it we can get rid of meson_uart_res_size().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:36:13 +02:00
Heiner Kallweit
5a2ce87bf2 serial: meson: remove dead code in meson_uart_change_speed
val is set in both branches of the if clause, therefore the two
removed lines are dead code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:56 +02:00
Heiner Kallweit
ba50f1df13 serial: meson: remove unneeded variable assignment in meson_serial_port_write
There's no need to set AML_UART_TX_EN in each call to
meson_serial_port_write. In addition to meson_uart_startup
set this flag in meson_serial_console_setup and
meson_serial_early_console_setup.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:56 +02:00
Heiner Kallweit
88f37d7071 serial: meson: fix setting number of stop bits
The stop bit value as to be or'ed, so far this worked only just by chance
because AML_UART_STOP_BIN_1SB is 0.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:56 +02:00
Andy Shevchenko
7b6d539944 tty/vt/keyboard: Remove AVR32 bits from the driver
AVR32 is gone. Now it's time to clean up the driver by removing
leftovers that was used by AVR32 related code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:55 +02:00
Geliang Tang
d1e06a4392 serial: pch_uart: use offset_in_page() macro
Use offset_in_page() macro instead of open-coding.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:55 +02:00
Geliang Tang
2b5cf14bd0 tty/serial: atmel: use offset_in_page() macro
Use offset_in_page() macro instead of open-coding.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:55 +02:00
Colin Ian King
228a9ff8fe drivers/tty/hvc: fix spelling mistake: "missmanaged" -> "mismanaged"
Trivial fix to spelling mistake in printk message

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:34:55 +02:00
Jan Kiszka
7dea8165f1 serial: exar: Preconfigure xr17v35x MPIOs as output
This is the safe default for GPIOs with unknown external wiring.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:26:40 +02:00
Peter Senna Tschudin
4dec2f119e imx-serial: RX DMA startup latency
18a4208 introduced a change to reduce the RX DMA latency on the first reception
when the serial port was opened for reading. However it was claiming a hardirq
unsafe lock after a hardirq safe lock which is not allowed and causes lockdep
to complain verbosely.

This patch changes the code to always start RX DMA earlier, instead of
relying on the flags used to open the serial port removing the code that
was looking for the serial file flags.

Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:26:40 +02:00
Stefan Wahren
56c607b509 tty: serdev-ttyport: return actual baudrate from ttyport_set_baudrate
Instead of returning the requested baudrate, we better return the
actual one because it isn't always the same.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Sjoerd Simons
352b926645 serial: sh-sci: Move uart_register_driver call to device probe
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically
happen during device probe call.

In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with overlapping major/minor numbers are
included.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Sjoerd Simons
bd8766b158 serial: pl010: Move uart_register_driver call to device probe
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically
happen during device probe call.

In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with overlapping major/minor numbers are
included.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Geert Uytterhoeven
1cf4a7efdc serial: sh-sci: Fix race condition causing garbage during shutdown
If DMA is enabled and used, a burst of old data may be seen on the
serial console during "poweroff" or "reboot".  uart_flush_buffer()
clears the circular buffer, but sci_port.tx_dma_len is not reset.
This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE -
sci_port.tx_dma_len) bytes.

To fix this, add a .flush_buffer() callback that resets
sci_port.tx_dma_len.

Inspired by commit 31ca2c63fd ("tty/serial: atmel: fix race
condition (TX+DMA)").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Jeremy Kerr
7fbcf3afe6 drivers/serial: Add driver for Aspeed virtual UART
This change adds a driver for the 16550-based Aspeed virtual UART
device. We use a similar process to the of_serial driver for device
probe, but expose some VUART-specific functions through sysfs too.

The VUART is two UART 'front ends' connected by their FIFO (no actual
serial line in between). One is on the BMC side (management controller)
and one is on the host CPU side.

This driver is for the BMC side. The sysfs files allow the BMC
userspace, which owns the system configuration policy, to specify at
what IO port and interrupt number the host side will appear to the host
on the Host <-> BMC LPC bus. It could be different on a different system
(though most of them use 3f8/4).

OpenPOWER host firmware doesn't like it when the host-side of the
VUART's FIFO is not drained. This driver only disables host TX discard
mode when the port is in use. We set the VUART enabled bit when we bind
to the device, and clear it on unbind.

We don't want to do this on open/release, as the host may be using this
bit to configure serial output modes, which is independent of whether
the devices has been opened by BMC userspace.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Joel Stanley
ea5244e2af serial: 8250: Add flag so drivers can avoid THRE probe
The probing of THRE irq behaviour assumes the other end will be reading
bytes out of the buffer in order to probe the port at driver init. In
some cases the other end cannot be relied upon to read these bytes, so
provide a flag for them to skip this step.

Bit 19 was chosen as the flags are a int and the top bits are taken.

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Andy Shevchenko
70b2fe355a serial: 8250_exar: Remove duplicate assignment
UPF_EXAR_EFR is set globally for each port enumerated by the driver.
Thus, no need to repeat this in individual ->setup() hook.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Vignesh R
84b40e3b57 serial: 8250: omap: Disable DMA for console UART
Kernel always writes log messages to console via
serial8250_console_write()->serial8250_console_putchar() which directly
accesses UART_TX register _without_ using DMA.

But, if other processes like systemd using same UART port, then these
writes are handled by a different code flow using 8250_omap driver where
there is provision to use DMA.

It seems that it is possible that both DMA and CPU might simultaneously
put data to UART FIFO and lead to potential loss of data due to FIFO
overflow and weird data corruption. This happens when both kernel
console and userspace tries to write simultaneously to the same UART
port. Therefore, disable DMA on kernel console port to avoid potential
race between CPU and DMA.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 16:19:16 +02:00
Okash Khawaja
1ab92da32e staging: speakup: add tty-based comms functions
This adds spk_ttyio.c file. It contains a set of functions which implement
those methods in spk_synth struct which relate to sending bytes out using
serial comms. Implementations in this file perform the same function but
using TTY subsystem instead. Currently synths access serial ports, directly
poking standard ISA ports by trying to steal them from serial driver. Some ISA
cards actually need this way of doing it, but most other synthesizers don't,
and can actually work by using the proper TTY subsystem through a new N_SPEAKUP
line discipline. So this adds the methods for drivers to switch to accessing
serial ports through the TTY subsystem, whenever appropriate.

Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-16 14:05:42 +02:00
Okash Khawaja
12e84c71b7 tty: export tty_open_by_driver
This exports tty_open_by_driver so that it can be called from other
places inside the kernel. The checks for null file pointer are based on
Alan Cox's patch here:
http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1215095.html.
Description below is quoted from it:

"[RFC] tty_port: allow a port to be opened with a tty that has no file handle

    Let us create tty objects entirely in kernel space. Untested proposal to
    show why all the ideas around rewriting half the uart stack are not needed.

    With this a kernel created non file backed tty object could be used to handle
    data, and set terminal modes. Not all ldiscs can cope with this as N_TTY in
    particular has to work back to the fs/tty layer.

    The tty_port code is however otherwise clean of file handles as far as I can
    tell as is the low level tty port write path used by the ldisc, the
    configuration low level interfaces and most of the ldiscs.

    Currently you don't have any exposure to see tty hangups because those are
    built around the file layer. However a) it's a fixed port so you probably
    don't care about that b) if you do we can add a callback and c) you almost
    certainly don't want the userspace tear down/rebuild behaviour anyway.

    This should however be sufficient if we wanted for example to enumerate all
    the bluetooth bound fixed ports via ACPI and make them directly available.

    It doesn't deal with the case of a user opening a port that's also kernel
    opened and that would need some locking out (so it returned EBUSY if bound
    to a kernel device of some kind). That needs resolving along with how you
    "up" or "down" your new bluetooth device, or enumerate it while providing
    the existing tty API to avoid regressions (and to debug)."

The exported funtion is used later in this patch set to gain access to tty_struct.

[changed export symbol level - gkh]

Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-16 14:04:49 +02:00
Linus Torvalds
291b38a756 Annotation of module parameters that specify device settings
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Merge tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull hw lockdown support from David Howells:
 "Annotation of module parameters that configure hardware resources
  including ioports, iomem addresses, irq lines and dma channels.

  This allows a future patch to prohibit the use of such module
  parameters to prevent that hardware from being abused to gain access
  to the running kernel image as part of locking the kernel down under
  UEFI secure boot conditions.

  Annotations are made by changing:

        module_param(n, t, p)
        module_param_named(n, v, t, p)
        module_param_array(n, t, m, p)

  to:

        module_param_hw(n, t, hwtype, p)
        module_param_hw_named(n, v, t, hwtype, p)
        module_param_hw_array(n, t, hwtype, m, p)

  where the module parameter refers to a hardware setting

  hwtype specifies the type of the resource being configured. This can
  be one of:

        ioport          Module parameter configures an I/O port
        iomem           Module parameter configures an I/O mem address
        ioport_or_iomem Module parameter could be either (runtime set)
        irq             Module parameter configures an I/O port
        dma             Module parameter configures a DMA channel
        dma_addr        Module parameter configures a DMA buffer address
        other           Module parameter configures some other value

  Note that the hwtype is compile checked, but not currently stored (the
  lockdown code probably won't require it). It is, however, there for
  future use.

  A bonus is that the hwtype can also be used for grepping.

  The intention is for the kernel to ignore or reject attempts to set
  annotated module parameters if lockdown is enabled. This applies to
  options passed on the boot command line, passed to insmod/modprobe or
  direct twiddling in /sys/module/ parameter files.

  The module initialisation then needs to handle the parameter not being
  set, by (1) giving an error, (2) probing for a value or (3) using a
  reasonable default.

  What I can't do is just reject a module out of hand because it may
  take a hardware setting in the module parameters. Some important
  modules, some ipmi stuff for instance, both probe for hardware and
  allow hardware to be manually specified; if the driver is aborts with
  any error, you don't get any ipmi hardware.

  Further, trying to do this entirely in the module initialisation code
  doesn't protect against sysfs twiddling.

  [!] Note that in and of itself, this series of patches should have no
      effect on the the size of the kernel or code execution - that is
      left to a patch in the next series to effect. It does mark
      annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in
      an already existing field"

* tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits)
  Annotate hardware config module parameters in sound/pci/
  Annotate hardware config module parameters in sound/oss/
  Annotate hardware config module parameters in sound/isa/
  Annotate hardware config module parameters in sound/drivers/
  Annotate hardware config module parameters in fs/pstore/
  Annotate hardware config module parameters in drivers/watchdog/
  Annotate hardware config module parameters in drivers/video/
  Annotate hardware config module parameters in drivers/tty/
  Annotate hardware config module parameters in drivers/staging/vme/
  Annotate hardware config module parameters in drivers/staging/speakup/
  Annotate hardware config module parameters in drivers/staging/media/
  Annotate hardware config module parameters in drivers/scsi/
  Annotate hardware config module parameters in drivers/pcmcia/
  Annotate hardware config module parameters in drivers/pci/hotplug/
  Annotate hardware config module parameters in drivers/parport/
  Annotate hardware config module parameters in drivers/net/wireless/
  Annotate hardware config module parameters in drivers/net/wan/
  Annotate hardware config module parameters in drivers/net/irda/
  Annotate hardware config module parameters in drivers/net/hamradio/
  Annotate hardware config module parameters in drivers/net/ethernet/
  ...
2017-05-10 19:13:03 -07:00
Linus Torvalds
8f3207c7ea TTY/Serial patches for 4.12-rc1
Here is the "big" TTY/Serial patch updates for 4.12-rc1
 
 Not a lot of new things here, the normal number of serial driver updates
 and additions, tiny bugs fixed, and some core files split up to make
 future changes a bit easier for Nicolas's "tiny-tty" work.
 
 All of these have been in linux-next for a while.  There will be a merge
 conflict with include/linux/serdev.h coming from the bluetooth tree
 merge, which we knew about, as we wanted some of the serdev changes to
 go in through that tree.  I'll send the expected merge result as a
 follow-on message.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the "big" TTY/Serial patch updates for 4.12-rc1

  Not a lot of new things here, the normal number of serial driver
  updates and additions, tiny bugs fixed, and some core files split up
  to make future changes a bit easier for Nicolas's "tiny-tty" work.

  All of these have been in linux-next for a while"

* tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (62 commits)
  serial: small Makefile reordering
  tty: split job control support into a file of its own
  tty: move baudrate handling code to a file of its own
  console: move console_init() out of tty_io.c
  serial: 8250_early: Add earlycon support for Palmchip UART
  tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
  vt: make mouse selection of non-ASCII consistent
  vt: set mouse selection word-chars to gpm's default
  imx-serial: Reduce RX DMA startup latency when opening for reading
  serial: omap: suspend device on probe errors
  serial: omap: fix runtime-pm handling on unbind
  tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
  serial: samsung: Remove useless spinlock
  serial: samsung: Add missing checks for dma_map_single failure
  serial: samsung: Use right device for DMA-mapping calls
  serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
  tty: fix comment typo s/repsonsible/responsible/
  tty: amba-pl011: Fix spurious TX interrupts
  serial: xuartps: Enable clocks in the pm disable case also
  serial: core: Re-use struct uart_port {name} field
  ...
2017-05-08 18:49:23 -07:00
Kees Cook
063246641d format-security: move static strings to const
While examining output from trial builds with -Wformat-security enabled,
many strings were found that should be defined as "const", or as a char
array instead of char pointer.  This makes some static analysis easier,
by producing fewer false positives.

As these are all trivial changes, it seemed best to put them all in a
single patch rather than chopping them up per maintainer.

Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Jes Sorensen <jes@trained-monkey.org>	[runner.c]
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Salil Mehta <salil.mehta@huawei.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kejian Yan <yankejian@huawei.com>
Cc: Daode Huang <huangdaode@hisilicon.com>
Cc: Qianqian Xie <xieqianqian@huawei.com>
Cc: Philippe Reynes <tremyfr@gmail.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Christian Gromm <christian.gromm@microchip.com>
Cc: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Cc: Jason Litzinger <jlitzingerdev@gmail.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:14 -07:00
Linus Torvalds
3ef2bc099d DeviceTree for 4.12:
- Fix sparse warnings in drivers/of/.
 
 - Add more overlay unittests.
 
 - Update dtc to v1.4.4-8-g756ffc4f52f6. This adds more checks on dts
 files such as unit-address formatting and stricter character sets for
 node and property names.
 
 - Add a common DT modalias function.
 
 - Move trivial-devices.txt up and out of i2c dir.
 
 - ARM NVIC interrupt controller binding.
 
 - Vendor prefixes for Sensirion, Dioo, Nordic, ROHM.
 
 - Correct some binding file locations.
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Merge tag 'devicetree-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull DeviceTree updates from Rob Herring:

 - fix sparse warnings in drivers/of/

 - add more overlay unittests

 - update dtc to v1.4.4-8-g756ffc4f52f6. This adds more checks on dts
   files such as unit-address formatting and stricter character sets for
   node and property names

 - add a common DT modalias function

 - move trivial-devices.txt up and out of i2c dir

 - ARM NVIC interrupt controller binding

 - vendor prefixes for Sensirion, Dioo, Nordic, ROHM

 - correct some binding file locations

* tag 'devicetree-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (24 commits)
  of: fix sparse warnings in fdt, irq, reserved mem, and resolver code
  of: fix sparse warning in of_pci_range_parser_one
  of: fix sparse warnings in of_find_next_cache_node
  of/unittest: Missing unlocks on error
  of: fix uninitialized variable warning for overlay test
  of: fix unittest build without CONFIG_OF_OVERLAY
  of: Add unit tests for applying overlays
  of: per-file dtc compiler flags
  fpga: region: add missing DT documentation for config complete timeout
  of: Add vendor prefix for ROHM Semiconductor
  of: fix "/cpus" reference leak in of_numa_parse_cpu_nodes()
  of: Add vendor prefix for Nordic Semiconductor
  dt-bindings: arm,nvic: Binding for ARM NVIC interrupt controller on Cortex-M
  dtc: update warning settings for new bus and node/property name checks
  scripts/dtc: Update to upstream version v1.4.4-8-g756ffc4f52f6
  scripts/dtc: automate getting dtc version and log in update script
  of: Add function for generating a DT modalias with a newline
  of: fix of_device_get_modalias returned length when truncating buffers
  Documentation: devicetree: move trivial-devices out of I2C realm
  dt-bindings: add vendor prefix for Dioo
  ..
2017-05-05 19:33:07 -07:00
Michal Hocko
d75da004c7 oom: improve oom disable handling
Tetsuo has reported that sysrq triggered OOM killer will print a
misleading information when no tasks are selected:

  sysrq: SysRq : Manual OOM execution
  Out of memory: Kill process 4468 ((agetty)) score 0 or sacrifice child
  Killed process 4468 ((agetty)) total-vm:43704kB, anon-rss:1760kB, file-rss:0kB, shmem-rss:0kB
  sysrq: SysRq : Manual OOM execution
  Out of memory: Kill process 4469 (systemd-cgroups) score 0 or sacrifice child
  Killed process 4469 (systemd-cgroups) total-vm:10704kB, anon-rss:120kB, file-rss:0kB, shmem-rss:0kB
  sysrq: SysRq : Manual OOM execution
  sysrq: OOM request ignored because killer is disabled
  sysrq: SysRq : Manual OOM execution
  sysrq: OOM request ignored because killer is disabled
  sysrq: SysRq : Manual OOM execution
  sysrq: OOM request ignored because killer is disabled

The real reason is that there are no eligible tasks for the OOM killer
to select but since commit 7c5f64f844 ("mm: oom: deduplicate victim
selection code for memcg and global oom") the semantic of out_of_memory
has changed without updating moom_callback.

This patch updates moom_callback to tell that no task was eligible which
is the case for both oom killer disabled and no eligible tasks.  In
order to help distinguish first case from the second add printk to both
oom_killer_{enable,disable}.  This information is useful on its own
because it might help debugging potential memory allocation failures.

Fixes: 7c5f64f844 ("mm: oom: deduplicate victim selection code for memcg and global oom")
Link: http://lkml.kernel.org/r/20170404134705.6361-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-03 15:52:10 -07:00
Linus Torvalds
89c9fea3c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  tty: fix comment for __tty_alloc_driver()
  init/main: properly align the multi-line comment
  init/main: Fix double "the" in comment
  Fix dead URLs to ftp.kernel.org
  drivers: Clean up duplicated email address
  treewide: Fix typo in xml/driver-api/basics.xml
  tools/testing/selftests/powerpc: remove redundant CFLAGS in Makefile: "-Wall -O2 -Wall" -> "-O2 -Wall"
  selftests/timers: Spelling s/privledges/privileges/
  HID: picoLCD: Spelling s/REPORT_WRTIE_MEMORY/REPORT_WRITE_MEMORY/
  net: phy: dp83848: Fix Typo
  UBI: Fix typos
  Documentation: ftrace.txt: Correct nice value of 120 priority
  net: fec: Fix typo in error msg and comment
  treewide: Fix typos in printk
2017-05-02 19:09:35 -07:00
Thadeu Lima de Souza Cascardo
6fbc8798d9 tty: fix comment for __tty_alloc_driver()
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@cascardo.eti.br>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-04-24 13:15:39 +02:00
David S. Miller
7b9f6da175 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
A function in kernel/bpf/syscall.c which got a bug fix in 'net'
was moved to kernel/bpf/verifier.c in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-20 10:35:33 -04:00
David Howells
3b60daf86b Annotate hardware config module parameters in drivers/tty/
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image.  Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify.  The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in drivers/tty/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jiri Slaby <jslaby@suse.com>
cc: linux-serial@vger.kernel.org
2017-04-20 12:02:32 +01:00
Nicolas Pitre
8e1c21f486 serial: small Makefile reordering
Move 21285 entry down alongside other UART drivers to be more consistent
with the rest of the file. It is kept before 8250 though, to preserve the
existing link ordering between those two.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 18:01:52 +02:00
Nicolas Pitre
a1235b3eb1 tty: split job control support into a file of its own
This makes it easier for job control to become optional and/or usable
independently from tty_io.c, as well as providing a nice purpose
separation. No logical changes from this patch.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 18:01:52 +02:00
Nicolas Pitre
fff0a2ca3a tty: move baudrate handling code to a file of its own
To allow reuse without the rest of the tty_ioctl code.
No logical changes from this patch.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 18:01:52 +02:00
Nicolas Pitre
0c688614dc console: move console_init() out of tty_io.c
All the console driver handling code lives in printk.c.
Move console_init() there as well so console support can still be used
when the TTY code is configured out. No logical changes from this patch.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 18:01:52 +02:00
Marc Gonzalez
72f1b85a04 serial: 8250_early: Add earlycon support for Palmchip UART
Define an OF early console for Palmchip UART, which can be enabled
by passing "earlycon" on the boot command line.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 17:47:42 +02:00
Timur Tabi
5a0722b898 tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
Define a new early console name for Qualcomm Datacenter Technologies
QDF2400 SOCs affected by erratum 44, instead of piggy-backing on "pl011".
Previously, to enable traditional (non-SPCR) earlycon, the documentation
said to specify "earlycon=pl011,<address>,qdf2400_e44", but the code was
broken and this didn't actually work.

So instead, the method for specifying the E44 work-around with traditional
earlycon is "earlycon=qdf2400_e44,<address>".  Both methods of earlycon
are now enabled with the same function.

Fixes: e53e597fd4 ("tty: pl011: fix earlycon work-around for QDF2400 erratum 44")
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Cc: stable <stable@vger.kernel.org> # 4.11
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 17:47:42 +02:00
Greg Kroah-Hartman
15a0654851 Merge 4.11-rc7 into tty-next
We want the tty patch revert in here to handle merges and future work
properly.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-17 09:07:37 +02:00
Greg Kroah-Hartman
a8983d01f9 Revert "tty: don't panic on OOM in tty_set_ldisc()"
This reverts commit 5362544beb as it is
reported to cause a reproducable crash.

Fixes: 5362544beb ("tty: don't panic on OOM in tty_set_ldisc()")
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <syzkaller@googlegroups.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
2017-04-14 10:59:56 +02:00
Sebastian Reichel
5659dab26f serdev: implement get/set tiocm
Add method for getting and setting tiocm.

Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2017-04-12 22:12:17 +02:00
Sebastian Reichel
b3f80c8f75 serdev: add serdev_device_wait_until_sent
Add method, which waits until the transmission buffer has been sent.
Note, that the change in ttyport_write_wakeup is related, since
tty_wait_until_sent will hang without that change.

Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2017-04-12 22:12:16 +02:00
Sebastian Reichel
2f09276769 tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
The UPF_BOOT_AUTOCONF flag is needed for proper
flow control support.

Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2017-04-12 22:12:16 +02:00
Adam Borowski
7f1534e172 vt: make mouse selection of non-ASCII consistent
For some reason a handful of ISO-8859-1 symbols are excluded from "word
chars" while the vast majority of Unicode is hard-coded as included, even
when inappropriate (we really would want to _not_ select line-drawing/etc).
Those symbols are: ¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿×÷

Thus, let's not special-case any non-ASCII anymore.  Attempts to set these
via ioctl will be silently ignored.

As an extra bonus, we debloat the kernel by 128 bytes.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11 21:39:15 +02:00
Adam Borowski
7d6d44aee0 vt: set mouse selection word-chars to gpm's default
Since forever, gpm was this code's only user, and it overrides the table on
start so the default was never seen -- until Bill Allombert's "consolation"
came in.  The in-kernel set is "A-Za-z0-9_" which fails to catch typical
file names, etc.  Let's change this to gpm's conservative default, ie
"-A-Za-z0-9_./"; most terminals include more, for example xfce4-terminal has
"-A-Za-z0-9,./?%&#:_=+@~".

There's some discussion at https://bugs.debian.org/846587

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11 21:39:14 +02:00
Peter Senna Tschudin
18a4208826 imx-serial: Reduce RX DMA startup latency when opening for reading
Reduce RX DMA start latency for the first reception when port is opened
for reading. Instead of waiting for an interrupt signaling data on RX
FIFO or data too old on RX FIFO, start RX DMA immediately when the
serial port is opened for reading.

Before this patch, the average RX DMA latency for the first reception
was 42489 microseconds with a standard deviation of 25721 microseconds
in 36 samples.

After the patch the average RX DMA latency for the first reception, when
the serial port is opened for reading, is 653 microseconds with a
standard deviation of 294 microseconds in 36 samples.

Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11 21:36:43 +02:00
Johan Hovold
77e6fe7fd2 serial: omap: suspend device on probe errors
Make sure to actually suspend the device before returning after a failed
(or deferred) probe.

Note that autosuspend must be disabled before runtime pm is disabled in
order to balance the usage count due to a negative autosuspend delay as
well as to make the final put suspend the device synchronously.

Fixes: 388bc26226 ("omap-serial: Fix the error handling in the omap_serial probe")
Cc: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11 21:36:43 +02:00
Johan Hovold
099bd73dc1 serial: omap: fix runtime-pm handling on unbind
An unbalanced and misplaced synchronous put was used to suspend the
device on driver unbind, something which with a likewise misplaced
pm_runtime_disable leads to external aborts when an open port is being
removed.

Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010
...
[<c046e760>] (serial_omap_set_mctrl) from [<c046a064>] (uart_update_mctrl+0x50/0x60)
[<c046a064>] (uart_update_mctrl) from [<c046a400>] (uart_shutdown+0xbc/0x138)
[<c046a400>] (uart_shutdown) from [<c046bd2c>] (uart_hangup+0x94/0x190)
[<c046bd2c>] (uart_hangup) from [<c045b760>] (__tty_hangup+0x404/0x41c)
[<c045b760>] (__tty_hangup) from [<c045b794>] (tty_vhangup+0x1c/0x20)
[<c045b794>] (tty_vhangup) from [<c046ccc8>] (uart_remove_one_port+0xec/0x260)
[<c046ccc8>] (uart_remove_one_port) from [<c046ef4c>] (serial_omap_remove+0x40/0x60)
[<c046ef4c>] (serial_omap_remove) from [<c04845e8>] (platform_drv_remove+0x34/0x4c)

Fix this up by resuming the device before deregistering the port and by
suspending and disabling runtime pm only after the port has been
removed.

Also make sure to disable autosuspend before disabling runtime pm so
that the usage count is balanced and device actually suspended before
returning.

Note that due to a negative autosuspend delay being set in probe, the
unbalanced put would actually suspend the device on first driver unbind,
while rebinding and again unbinding would result in a negative
power.usage_count.

Fixes: 7e9c8e7dbf ("serial: omap: make sure to suspend device before remove")
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-11 21:36:43 +02:00
Sebastian Reichel
1b775de970 tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
The UPF_BOOT_AUTOCONF flag is needed for proper
flow control support.

Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Marek Szyprowski
469f813ffe serial: samsung: Remove useless spinlock
Spinlock taken only for dma_map_single() for TX buffer is completely
useless and doesn't protect anything, so remove it to simplify the code.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Marek Szyprowski
500fcc08a3 serial: samsung: Add missing checks for dma_map_single failure
This patch adds missing checks for dma_map_single() failure and proper error
reporting. Although this issue was harmless on ARM architecture, it is always
good to use the DMA mapping API in a proper way. This patch fixes the following
DMA API debug warning:

WARNING: CPU: 1 PID: 3785 at lib/dma-debug.c:1171 check_unmap+0x8a0/0xf28
dma-pl330 121a0000.pdma: DMA-API: device driver failed to check map error[device address=0x000000006e0f9000] [size=4096 bytes] [mapped as single]
Modules linked in:
CPU: 1 PID: 3785 Comm: (agetty) Tainted: G        W       4.11.0-rc1-00137-g07ca963-dirty #59
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c072a114>] (check_unmap+0x8a0/0xf28)
[<c072a114>] (check_unmap) from [<c072a834>] (debug_dma_unmap_page+0x98/0xc8)
[<c072a834>] (debug_dma_unmap_page) from [<c0803874>] (s3c24xx_serial_shutdown+0x314/0x52c)
[<c0803874>] (s3c24xx_serial_shutdown) from [<c07f5124>] (uart_port_shutdown+0x54/0x88)
[<c07f5124>] (uart_port_shutdown) from [<c07f522c>] (uart_shutdown+0xd4/0x110)
[<c07f522c>] (uart_shutdown) from [<c07f6a8c>] (uart_hangup+0x9c/0x208)
[<c07f6a8c>] (uart_hangup) from [<c07c426c>] (__tty_hangup+0x49c/0x634)
[<c07c426c>] (__tty_hangup) from [<c07c78ac>] (tty_ioctl+0xc88/0x16e4)
[<c07c78ac>] (tty_ioctl) from [<c03b5f2c>] (do_vfs_ioctl+0xc4/0xd10)
[<c03b5f2c>] (do_vfs_ioctl) from [<c03b6bf4>] (SyS_ioctl+0x7c/0x8c)
[<c03b6bf4>] (SyS_ioctl) from [<c010b4a0>] (ret_fast_syscall+0x0/0x3c)

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.10+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Marek Szyprowski
768d64f491 serial: samsung: Use right device for DMA-mapping calls
Driver should provide its own struct device for all DMA-mapping calls instead
of extracting device pointer from DMA engine channel. Although this is harmless
from the driver operation perspective on ARM architecture, it is always good
to use the DMA mapping API in a proper way. This patch fixes following DMA API
debug warning:

WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4
samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4)
[<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8)
[<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8)
[<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c)

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Uwe Kleine-König
e61c38d85b serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which
is the reset default) and the opposite side pulls the respective line to
its active level the irq triggers after it is requested in .probe.

These irqs were already disabled in .startup but this might be too late.

Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is
done very late which is critical as it also controls direction of some
pins.

So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken
irqs in DTE mode there before requesting irqs.

Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:54:07 +02:00
Thadeu Lima de Souza Cascardo
87838ae3af tty: fix comment typo s/repsonsible/responsible/
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@cascardo.eti.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:54:07 +02:00
Jayachandran C
7d05587c9e tty: amba-pl011: Fix spurious TX interrupts
On SMP systems, we see a lot of spurious TX interrupts when a
program generates a steady stream of output to the pl011 UART.

The problem can be easily seen when one CPU generates the output
while another CPU handles the pl011 interrupts, and the rate of
output is low enough not to fill the TX FIFO. The problem seems
to be:

    -- CPU a --                        -- CPU b --
   (take port lock)
   pl011_start_tx
      pl011_start_tx_pio
         enable TXIM in REG_IMSC   ->  causes uart tx intr (pl011_int)
         pl011_tx_chars                pl011_int
            ...tx chars, all done...       (wait for port lock)
            pl011_stop_tx                   .
               disable TXIM                 .
    (release port lock)            ->      (take port lock)
                                           check for TXIM, not enabled
                                           (release port lock)
                                           return IRQ_NONE

Enabling the TXIM in pl011_start_tx_pio() causes the interrupt
to be generated and delivered to CPU b, even though pl011_tx_chars()
is able to complete the TX and then disable the tx interrupt.

Fix this by enabling TXIM only after pl011_tx_chars, if it is needed.
pl011_tx_chars will return a boolean indicating whether the TX
interrupts have to be enabled.

Debugged-by: Vijaya Kumar <Vijaya.Kumar@cavium.com>
Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:54:07 +02:00
Shubhrajyoti Datta
ecfc5771ef serial: xuartps: Enable clocks in the pm disable case also
When Power management is disabled then the clocks are not getting
enabled. This patch enables it for the !PM case also.
While at it also pm_runtime_set_active is called before
calling pm_runtime_enable.

Reported-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:54:07 +02:00
Andy Shevchenko
cade3580f7 serial: core: Re-use struct uart_port {name} field
Since we have port name stored in struct uart_port, we better to use
that one instead of open coding.

This will make it one place source for easier maintenance or
modifications.

While here, replace printk(KERN_INFO ) by pr_info(). It seems last printk()
call in serial_core.c.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:51:57 +02:00
Andrey Smirnov
6fe729c4bd serdev: Add serdev_device_write subroutine
Add serdev_device_write() a blocking call allowing to transfer
arbitraty amount of data (potentially exceeding amount that
serdev_device_write_buf can process in a single call)

To support that, also add serdev_device_write_wakeup().

Drivers wanting to use full extent of serdev_device_write
functionality are expected to provide serdev_device_write_wakeup() as
a sole handler of .write_wakeup event or call it as a part of driver's
custom .write_wakeup code.

Because serdev_device_write() subroutine is a superset of
serdev_device_write_buf() the patch re-impelements latter is terms of
the former. For drivers wanting to just use serdev_device_write_buf()
.write_wakeup handler is optional.

Cc: cphealy@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:51:00 +02:00
Wei Qiao
e1dc9b0805 serial: sprd: adjust TIMEOUT to a big value
SPRD_TIMEOUT was 256, which is too small to wait until the status
switched to workable in a while loop, so that the earlycon could
not work correctly.

Signed-off-by: Wei Qiao <wei.qiao@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:42:47 +02:00
David S. Miller
6f14f443d3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Mostly simple cases of overlapping changes (adding code nearby,
a function whose name changes, for example).

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-06 08:24:51 -07:00
Eric Biggers
5e35141066 net: ibm: emac: remove unused sysrq handler for 'c' key
Since commit d6580a9f15 ("kexec: sysrq: simplify sysrq-c handler"),
the sysrq handler for the 'c' key has been sysrq_crash_op.  Debugging
code in the ibm_emac driver also tries to register a handler for the 'c'
key, but this has no effect because register_sysrq_key() doesn't replace
existing handlers.  Since evidently no one has cared enough to fix this
in the last 8 years, and it's very rare for drivers to register sysrq
handlers (for good reason), just remove the dead code.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-05 07:26:18 -07:00
Greg Kroah-Hartman
9ccd8d7445 Merge 4.11-rc5 into tty-next
We want the serial fixes in here as well to handle merge issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-03 14:18:16 +02:00
Linus Torvalds
128c434a70 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "This update provides:

   - make the scheduler clock switch to unstable mode smooth so the
     timestamps stay at microseconds granularity instead of switching to
     tick granularity.

   - unbreak perf test tsc by taking the new offset into account which
     was added in order to proveide better sched clock continuity

   - switching sched clock to unstable mode runs all clock related
     computations which affect the sched clock output itself from a work
     queue. In case of preemption sched clock uses half updated data and
     provides wrong timestamps. Keep the math in the protected context
     and delegate only the static key switch to workqueue context.

   - remove a duplicate header include"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/headers: Remove duplicate #include <linux/sched/debug.h> line
  sched/clock: Fix broken stable to unstable transfer
  sched/clock, x86/perf: Fix "perf test tsc"
  sched/clock: Fix clear_sched_clock_stable() preempt wobbly
2017-04-02 09:25:10 -07:00
Timur Tabi
e53e597fd4 tty: pl011: fix earlycon work-around for QDF2400 erratum 44
The work-around for the Qualcomm Datacenter Technologies QDF2400
erratum 44 sets the "qdf2400_e44_present" global variable if the
work-around is needed.  However, this check does not happen until after
earlycon is initialized, which means the work-around is not
used, and the console hangs as soon as it displays one character.

Fixes: d8a4995bce ("tty: pl011: Work around QDF2400 E44 stuck BUSY bit")
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-01 11:07:29 +02:00
Paul Gortmaker
49e1590c2e serial: 8250_EXAR: fix duplicate Kconfig text and add missing help text
In commit d0aeaa83f0 ("serial: exar:
split out the exar code from 8250_pci") the exar driver got its own
Kconfig.  However the text for the new option was never changed from
the original 8250_PCI text, and hence it appears confusing when you
get asked the same question twice:

  8250/16550 PCI device support (SERIAL_8250_PCI) [Y/n/m/?] (NEW)
    8250/16550 PCI device support (SERIAL_8250_EXAR) [Y/n/m] (NEW)

Adding to the confusion, is that there is no help text for this new
option to indicate it is specific to a certain family of cards.

Fix both issues at the same time, as well as the space vs. tab issues
introduced in the same commit.

Fixes: d0aeaa83f0 ("serial: exar: split out the exar code from 8250_pci")
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:20 +02:00
Nicolas Ferre
497e1e16f4 tty/serial: atmel: fix TX path in atmel_console_write()
A side effect of 89d8232411 ("tty/serial: atmel_serial: BUG: stop DMA
from transmitting in stop_tx") is that the console can be called with
TX path disabled. Then the system would hang trying to push charecters
out in atmel_console_putchar().

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Fixes: 89d8232411 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting
in stop_tx")
Cc: stable <stable@vger.kernel.org>	#4.4+
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:20 +02:00
Richard Genoud
31ca2c63fd tty/serial: atmel: fix race condition (TX+DMA)
If uart_flush_buffer() is called between atmel_tx_dma() and
atmel_complete_tx_dma(), the circular buffer has been cleared, but not
atmel_port->tx_len.
That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE -
atmel_port->tx_len) bytes).

Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:19 +02:00
Uwe Kleine-König
a6040bc610 serial: mxs-auart: Fix baudrate calculation
The reference manual for the i.MX28 recommends to calculate the divisor
as

	divisor = (UARTCLK * 32) / baud rate, rounded to the nearest integer

, so let's do this. For a typical setup of UARTCLK = 24 MHz and baud
rate = 115200 this changes the divisor from 6666 to 6667 and so the
actual baud rate improves from 115211.521 Bd (error ≅ 0.01 %) to
115194.240 Bd (error ≅ 0.005 %).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 17:26:19 +02:00
Stefan Agner
abf1e0a980 tty: serial: fsl_lpuart: lock port on console write
The console write code is not entirely race free (e.g. the operations
to disabling the UART interrupts are not atomic) hence locking is
required. This has been become apparent with the PREEMPT RT patchset
applied: With the fully preemptible kernel configuration the system
often ended up in a freeze already at startup.

Disable interrupts and lock using read_lock_irqsave. Try to lock in
the sysrq/oops case, but don't bother if locking fails.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Tobias Klauser
4d9d7d896d serial: altera_uart: add earlycon support
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_uart.

Add earlycon support to altera_uart so that other archs may use it.
Also, this (together with the corresponding patch for altera_jtaguart)
will allow the early printk implementation in arch/nios2 to be removed
in a future patch.

Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Tim Gardner
a4199f5eb8 tty: Disable default console blanking interval
BugLink: http://bugs.launchpad.net/bugs/869017

Console blanking is not enabling DPMS power saving (thereby negating any
power-saving benefit), and is simply turning the screen content blank. This
means that any crash output is invisible which is unhelpful on a server
(virtual or otherwise).

Furthermore, CRT burn in concerns should no longer govern the default case.
Affected users could always set consoleblank on the kernel command line.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Vignesh R
b2c663d155 serial: 8250: 8250_core: Fix irq name for 8250 serial IRQ
Using dev_name() as IRQ name during request_irq() might be misleading in
case of serial over PCI. Therefore identify serial port IRQ using
uart_port's name field. This will help mapping IRQs to appropriate
ttySN(where N is the serial port index) instances.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Vignesh R
f7048b1590 tty: serial_core: Add name field to uart_port struct
Introduce a field to store name of uart_port that can be used to easily
identify UART port instances on a system that has more than one UART
instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N
is number that particular UART instance.
This field will be useful when printing debug info for a particular port
or in register IRQs with unique IRQ name. Port name is populated during
uart_add_one_port().

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 16:56:10 +02:00
Jan Kiszka
7cd3e9dbdd serial: 8250_lpss: Unconditionally set PCI master for Quark
MSI needs it as well.

Should have no practical impact, though, as DMA is always available on
the Quark. But given the few users of pci_alloc_irq_vectors so far, this
incorrect pattern may spread otherwise.

Fixes: 3f3a46951e ("serial: 8250_lpss: set PCI master only for private DMA")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:36:54 +02:00
Geert Uytterhoeven
cfa6eb2391 serial: sh-sci: Fix (AUTO)RTS in sci_init_pins()
If a UART has dedicated RTS/CTS pins, and hardware control flow is
disabled (or AUTORTS is not yet effective), changing any serial port
configuration deasserts RTS, as .set_termios() calls sci_init_pins().

To fix this, consider the current (AUTO)RTS state when (re)initializing
the pins.  Note that for SCIFA/SCIFB, AUTORTS needs explicit
configuration of the RTS# pin function, while (H)SCIF handles this
automatically.

Fixes: d2b9775d79 ("serial: sh-sci: Correct pin initialization on (H)SCIF")
Fixes: e9d7a45a03 ("serial: sh-sci: Add pin initialization for SCIFA/SCIFB")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:06 +02:00
Geert Uytterhoeven
5f76895e4c serial: sh-sci: Fix late enablement of AUTORTS
When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised.  However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.

To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).

Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc25 ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Geert Uytterhoeven
e37f712f76 serial: sh-sci: Fix hang in sci_reset()
When the .set_termios() callback resets the UART, it first waits (busy
loops) until all characters in the transmit FIFO have been transmitted,
to prevent a port configuration change from impacting these characters.

However, if the UART has dedicated RTS/CTS hardware flow control
enabled, these characters may have been stuck in the FIFO due to CTS not
being asserted by the remote side.

  - When a new user opens the port, .set_termios() is called while
    transmission is still disabled, leading to an infinite loop:

	NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!

  - When an active user changes port configuration without waiting for
    the draining of the transmit FIFO, this may also block indefinitely,
    until CTS is asserted by the remote side.

This has been observed with SCIFA (on r8a7740/armadillo), and SCIFB and
HSCIF (on r8a7791/koelsch).

To fix this, remove the code that waits for the draining of the transmit
FIFO.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Lee Jones
b5090cb46e serial: st-asc: Change default baudrate from 9600 to 115200
9600 is old school.

Most applications use 115200 as the default baud these days.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Lionel Debieve
ef49ffd8b5 tty: serial: st-asc: Make the locking RT aware
The lock is a sleeping lock and local_irq_save() is not the
standard implementation now. Working for both -RT and non
RT.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 15:29:05 +02:00
Denis Kirjanov
19fa6e601b tty/hvc_console: fix console lock ordering with spinlock
hvc_remove() takes a spin lock first then acquires the console
semaphore. This situation can easily lead to a deadlock scenario
where we call scheduler with spin lock held.

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Johan Hovold
93857edd98 tty: reset termios state on device registration
Free any saved termios data when registering a tty device so that the
termios state is reset when reusing a minor number.

This is useful for hot-pluggable buses such as USB where it does not
make much sense to reuse saved termios data from an unrelated device
when a new device is later plugged in.

This specifically avoids a situation where the new device does not have
the carrier-detect signal wired, but the saved termios state has CLOCAL
cleared, effectively preventing the port from being opened in blocking
mode as noted by Jan Kundrát <jan.kundrat@cesnet.cz>.

Note that clearing the saved data at deregistration would not work as
the device could still be open.

Also note that the termios data is not reset for drivers with
TTY_DRIVER_DYNAMIC_ALLOC set (e.g. legacy pty) as their character device
is registered at driver registration and could theoretically already
have been opened (and pty termios state is never saved anyway).

Reported-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Johan Hovold
16b00ae82d tty: drop obsolete termios_locked comments
Drop comments about tty-driver termios_locked structures, which have
been outdated since commit fe6e29fdb1 ("tty: simplify ktermios
allocation").

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Johan Hovold
6a7e6f78c2 tty: close race between device register and open
The tty class device is currently not registered until after the
character device has been registered thereby leaving a small window
were a racing open could end up with a NULL tty->dev pointer due to the
class-device lookup failing in alloc_tty_struct.

Close this race by registering the class device before the character
device while making sure to defer the user-space uevent notification
until after the character device has been registered.

Note that some tty drivers expect a valid tty->dev and would misbehave
or crash otherwise. Some line disciplines also currently dereference the
class device unconditionally despite the fact that not every tty is
guaranteed to have one (Unix98 pty), but this is being fixed separately.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-31 11:37:13 +02:00
Greg Kroah-Hartman
53c1cf4281 Merge 4.11-rc4 into tty-next
We want the tty/serial fixes in here to handle bugfixes and merge
issues.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-29 08:58:53 +02:00
Greg Kroah-Hartman
896d81fefe Revert "tty: Fix ldisc crash on reopened tty"
This reverts commit 71472fa9c5.  It caused
merge issues, and Dmitry found some review issues.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-29 07:50:49 +02:00
Ingo Molnar
658b299580 sched/headers: Remove duplicate #include <linux/sched/debug.h> line
Vito Caputo reported that the sched.h split-up series
introduced a duplicate #include <linux/sched/debug.h> line
in drivers/tty/vt/keyboard.c.

Remove it.

Reported-by: Vito Caputo <vcaputo@pengaru.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-28 09:56:03 +02:00
Linus Torvalds
f1638fc65e TTY/Serial driver fixes for 4.11-rc4
Here are some tty and serial driver fixes for 4.11-rc4.  One of these
 fix a long-standing issue in the ldisc code that was found by Dmitry
 Vyukov with his great fuzzing work.  The other fixes resolve other
 reported issues, and there is one revert of a patch in 4.11-rc1 that
 wasn't correct.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some tty and serial driver fixes for 4.11-rc4.

  One of these fix a long-standing issue in the ldisc code that was
  found by Dmitry Vyukov with his great fuzzing work. The other fixes
  resolve other reported issues, and there is one revert of a patch in
  4.11-rc1 that wasn't correct.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix data race in tty_ldisc_ref_wait()
  tty: don't panic on OOM in tty_set_ldisc()
  Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
  tty: acpi/spcr: QDF2400 E44 checks for wrong OEM revision
  serial: 8250_dw: Fix breakage when HAVE_CLK=n
  serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
2017-03-26 11:03:42 -07:00
Rob Herring
0634c29589 of: Add function for generating a DT modalias with a newline
The modalias sysfs attr is lacking a newline for DT aliases on platform
devices. The macio and ibmebus correctly add the newline, but open code it.
Introduce a new function, of_device_modalias(), that fills the buffer with
the modalias including the newline and update users of the old
of_device_get_modalias function.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-22 14:56:13 -05:00
Linus Torvalds
4719177780 GPIO fixes for the v4.11 series:
- Set the parent on the Altera A10SR driver, also fix
   high level IRQs.
 
 - Fix error path on the mockup driver.
 
 - Compilation noise about unused functions fixed.
 
 - Fix missed interrupts on the MCP23S08 expander, this is also
   tagged for stable.
 
 - Retire the interrim helpers devm_get_gpiod_from_child() used
   to smoothen merging in the merge window.
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 =dTnd
 -----END PGP SIGNATURE-----

Merge tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO fixes from Linus Walleij:
 "Here is the first set of GPIO fixes for 4.11. It was delayed a bit
  beacuse I was chicken when linux-next was not rotating last week.

  This hits the ST serial driver in drivers/tty/serial and that has an
  ACK from Greg, he suggested to keep the old GPIO fwnode API around to
  smoothen things in the merge Windod and those have now served their
  purpose so we take them out and convert the last driver to the new
  API.

  Apart from that it's fixes as usual.

  Summary:

   - set the parent on the Altera A10SR driver, also fix high level
     IRQs.

   - fix error path on the mockup driver.

   - compilation noise about unused functions fixed.

   - fix missed interrupts on the MCP23S08 expander, this is also tagged
     for stable.

   - retire the interrim helpers devm_get_gpiod_from_child() used to
     smoothen merging in the merge window"

* tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio:mcp23s08 Fixed missing interrupts
  serial: st-asc: Use new GPIOD API to obtain RTS pin
  gpio: altera: Use handle_level_irq when configured as a level_high
  gpio: xgene: mark PM functions as __maybe_unused
  gpio: mockup: return -EFAULT if copy_from_user() fails
  gpio: altera-a10sr: Set gpio_chip parent property
2017-03-21 13:01:53 -07:00
Philipp Zabel
acbdad8dd1 serial: 8250_dw: simplify optional reset handling
As of commit bb475230b8 ("reset: make optional functions really
optional"), the reset framework API calls use NULL pointers to describe
optional, non-present reset controls.

This allows to return errors from devm_reset_control_get_optional and to
call reset_control_(de)assert unconditionally.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:12 +09:00
Jiri Slaby
22077b091a tty: serial_core, remove state checks in uart_poll*
Coverity complains about uart_state checks in polling functions. And it
is indeed correct. We do something like this:
	struct uart_state *state = drv->state + line;
	if (!state)
		return;

Adding 'line' to drv->state would move the potential NULL pointer to
something near NULL and the check is useless. Even if we checked pure
drv->state, nothing guarantees it is not freed and NULLed after the
check. So if the only user of this interface (kgdboc) needs to assure
something, this is neither the correct thing, nor place to do so.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:11 +09:00
Lukas Redlinger
fab8a02b73 serial: 8250_fintek: Enable high speed mode on Fintek F81866
Fintek F81866 supports baud rates higher than 115200 but needs to raise
it's clock speed from 1.84 to 14.76 MHz.
This is eight times faster, so gives 921600 as resulting baud_base.

F81866 clock register 0xf2:
    Bit 7-2    reserved
    Bit 1-0    00: 1.8432MHz
               01: 18.432MHz
               10: 24MHz
               11: 14.769MHz

Signed-off-by: Lukas Redlinger <rel+kernel@agilox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:17:11 +09:00
Peter Hurley
71472fa9c5 tty: Fix ldisc crash on reopened tty
If the tty has been hungup, the ldisc instance may have been destroyed.
Continued input to the tty will be ignored as long as the ldisc instance
is not visible to the flush_to_ldisc kworker. However, when the tty
is reopened and a new ldisc instance is created, the flush_to_ldisc
kworker can obtain an ldisc reference before the new ldisc is
completely initialized. This will likely crash:

 BUG: unable to handle kernel paging request at 0000000000002260
 IP: [<ffffffff8152dc5d>] n_tty_receive_buf_common+0x6d/0xb80
 PGD 2ab581067 PUD 290c11067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP
 Modules linked in: nls_iso8859_1 ip6table_filter [.....]
 CPU: 2 PID: 103 Comm: kworker/u16:1 Not tainted 4.6.0-rc7+wip-xeon+debug #rc7+wip
 Hardware name: Dell Inc. Precision WorkStation T5400  /0RW203, BIOS A11 04/30/2012
 Workqueue: events_unbound flush_to_ldisc
 task: ffff8802ad16d100 ti: ffff8802ad31c000 task.ti: ffff8802ad31c000
 RIP: 0010:[<ffffffff8152dc5d>]  [<ffffffff8152dc5d>] n_tty_receive_buf_common+0x6d/0xb80
 RSP: 0018:ffff8802ad31fc70  EFLAGS: 00010296
 RAX: 0000000000000000 RBX: ffff8802aaddd800 RCX: 0000000000000001
 RDX: 00000000ffffffff RSI: ffffffff810db48f RDI: 0000000000000246
 RBP: ffff8802ad31fd08 R08: 0000000000000000 R09: 0000000000000001
 R10: ffff8802aadddb28 R11: 0000000000000001 R12: ffff8800ba6da808
 R13: ffff8802ad18be80 R14: ffff8800ba6da858 R15: ffff8800ba6da800
 FS:  0000000000000000(0000) GS:ffff8802b0a00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000002260 CR3: 000000028ee5d000 CR4: 00000000000006e0
 Stack:
  ffffffff81531219 ffff8802aadddab8 ffff8802aadddde0 ffff8802aadddd78
  ffffffff00000001 ffff8800ba6da858 ffff8800ba6da860 ffff8802ad31fd30
  ffffffff81885f78 ffffffff81531219 0000000000000000 0000000200000000
 Call Trace:
  [<ffffffff81531219>] ? flush_to_ldisc+0x49/0xd0
  [<ffffffff81885f78>] ? mutex_lock_nested+0x2c8/0x430
  [<ffffffff81531219>] ? flush_to_ldisc+0x49/0xd0
  [<ffffffff8152e784>] n_tty_receive_buf2+0x14/0x20
  [<ffffffff81530cb2>] tty_ldisc_receive_buf+0x22/0x50
  [<ffffffff8153128e>] flush_to_ldisc+0xbe/0xd0
  [<ffffffff810a0ebd>] process_one_work+0x1ed/0x6e0
  [<ffffffff810a0e3f>] ? process_one_work+0x16f/0x6e0
  [<ffffffff810a13fe>] worker_thread+0x4e/0x490
  [<ffffffff810a13b0>] ? process_one_work+0x6e0/0x6e0
  [<ffffffff810a7ef2>] kthread+0xf2/0x110
  [<ffffffff810ae68c>] ? preempt_count_sub+0x4c/0x80
  [<ffffffff8188ab52>] ret_from_fork+0x22/0x50
  [<ffffffff810a7e00>] ? kthread_create_on_node+0x220/0x220
 Code: ff ff e8 27 a0 35 00 48 8d 83 78 05 00 00 c7 45 c0 00 00 00 00 48 89 45 80 48
       8d 83 e0 05 00 00 48 89 85 78 ff ff ff 48 8b 45 b8 <48> 8b b8 60 22 00 00 48
       8b 30 89 f8 8b 8b 88 04 00 00 29 f0 8d
 RIP  [<ffffffff8152dc5d>] n_tty_receive_buf_common+0x6d/0xb80
  RSP <ffff8802ad31fc70>
 CR2: 0000000000002260

Ensure the kworker cannot obtain the ldisc reference until the new ldisc
is completely initialized.

Fixes: 892d1fa7ea ("tty: Destroy ldisc instance on hangup")
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:16:09 +09:00
Wang YanQing
77dae61344 tty: pty: Fix ldisc flush after userspace become aware of the data already
While using emacs, cat or others' commands in konsole with recent
kernels, I have met many times that CTRL-C freeze konsole. After
konsole freeze I can't type anything, then I have to open a new one,
it is very annoying.

See bug report:
https://bugs.kde.org/show_bug.cgi?id=175283

The platform in that bug report is Solaris, but now the pty in linux
has the same problem or the same behavior as Solaris :)

It has high possibility to trigger the problem follow steps below:
Note: In my test, BigFile is a text file whose size is bigger than 1G
1:open konsole
1:cat BigFile
2:CTRL-C

After some digging, I find out the reason is that commit 1d1d14da12
("pty: Fix buffer flush deadlock") changes the behavior of pty_flush_buffer.

Thread A                                 Thread B
--------                                 --------
1:n_tty_poll return POLLIN
                                         2:CTRL-C trigger pty_flush_buffer
                                             tty_buffer_flush
                                               n_tty_flush_buffer
3:attempt to check count of chars:
  ioctl(fd, TIOCINQ, &available)
  available is equal to 0

4:read(fd, buffer, avaiable)
  return 0

5:konsole close fd

Yes, I know we could use the same patch included in the BUG report as
a workaround for linux platform too. But I think the data in ldisc is
belong to application of another side, we shouldn't clear it when we
want to flush write buffer of this side in pty_flush_buffer. So I think
it is better to disable ldisc flush in pty_flush_buffer, because its new
hehavior bring no benefit except that it mess up the behavior between
POLLIN, and TIOCINQ or FIONREAD.

Also I find no flush_buffer function in others' tty driver has the
same behavior as current pty_flush_buffer.

Fixes: 1d1d14da12 ("pty: Fix buffer flush deadlock")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:16:09 +09:00
Sam Povilus
b44b96a060 uartlite: Adding a kernel parameter for the number of uartlites
The number of uartlites should be set by a kernel parameter instead of
using a #define. This allows the user to set the number of uartlites
using only kconfig and not modifying kernel source.

The uartlite is used by FPGAs that support a basically unlimited number
of uarts so limiting it at 16 dosn't make sense as users might need more
than that.

Signed-off-by: Sam Povilus <kernel.development@povil.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:30 +09:00
Shubhrajyoti Datta
81e33b51ed serial: xuartps: Cleanup the clock enable
The core handles the clocking now. Remove the clock disable in
suspend. In resume we enable the clocks and disable after register
write.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Tobias Klauser
0dcc0542a0 serial: altera_jtaguart: add earlycon support
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_jtaguart
(and altera_uart for that matter).

Add earlycon support to altera_jtaguart so that other archs may use it. Also,
this will allow the early printk implementation in arch/nios2 to eventually be
removed in a future patch.

Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Tobias Klauser
47baf1ad81 tty: n_gsm: Use net_device_stats from struct net_device
Instead of using a private copy of struct net_device_stats in struct
gsm_mux_net, use stats from struct net_device. Also remove
the now unnecessary .ndo_get_stats function.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Joe Perches
d437fa9109 drivers/tty: Convert remaining uses of pr_warning to pr_warn
To enable eventual removal of pr_warning

This makes pr_warn use consistent for drivers/tty

Prior to this patch, there were 2 uses of pr_warning and
23 uses of pr_warn in drivers/tty

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:14:00 +09:00
Dmitry Vyukov
a4a3e06114 tty: fix data race in tty_ldisc_ref_wait()
tty_ldisc_ref_wait() checks tty->ldisc under tty->ldisc_sem.
But if ldisc==NULL it releases them sem and reloads
tty->ldisc without holding the sem. This is wrong and
can lead to returning non-NULL ldisc without protection.

Don't reload tty->ldisc second time.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:07:10 +09:00
Dmitry Vyukov
5362544beb tty: don't panic on OOM in tty_set_ldisc()
If tty_ldisc_open() fails in tty_set_ldisc(), it tries to go back
to the old discipline or N_TTY. But that can fail as well, in such
case it panics. This is not a graceful way to handle OOM.

Leave ldisc==NULL if all attempts fail instead.
Also use existing tty_ldisc_reinit() helper function instead of
tty_ldisc_restore(). Also don't WARN/BUG in tty_ldisc_reinit()
if N_TTY fails, which would have the same net effect of bringing
kernel down on OOM. Instead print a single line message about
what has happened.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:07:10 +09:00
Aleksey Makarov
b767ad726c Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
The original patch makes the condition always true, so it is wrong.

It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.

s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.

This reverts commit aea9a80ba9.

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-17 14:04:06 +09:00
Lee Jones
0043c1dfbe serial: st-asc: Use new GPIOD API to obtain RTS pin
The commits mentioned below adapt the GPIO API to allow more information
to be passed directly through devm_get_gpiod_from_child() in the first
instance.  This facilitates the removal of subsequent calls, such as
gpiod_direction_output().  This patch firstly moves to utilise the new
API and secondly removes the now superfluous call do set the direction.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Also drop the header file dummies that only this driver was using]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-03-14 10:36:41 +01:00
Shubhrajyoti Datta
d62100f1aa serial: xilinx_uartps: Add pm runtime support
Adds pm runtime support to xilinx uart ps.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 11:01:40 +08:00
Vignesh R
f48180a70e serial: 8250: 8250_core: Use dev_name() during request_irq()
Passing "serial" as name during request_irq() results in all serial port
irqs have same name. This does not help much to easily identify which
irq belongs to which serial port instance. Therefore pass dev_name()
during request_irq() so that better identifiable name is listed for
serial ports in cat /proc/interrupts output.

Output of cat /proc/interrupts
Before this patch:
 26:        689          0     GICv2 309 Edge      serial
After this patch:
 26:        696          0     GICv2 309 Edge      2530c00.serial

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 11:01:40 +08:00
Elena Reshetova
22a33651a5 drivers: convert sbd_duart.map_guard from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 11:01:40 +08:00
Richard Genoud
8961df8950 tty/serial: atmel: move atmel_serial header into driver directory
atmel_serial.h is only used by atmel_serial.c, so there's no need for
it to lie in include/linux.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Andy Shevchenko
2b57b7ff9d serial: 8250_exar: Fix spelling of "driver"
Fix typo in "Dricer".

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Alexandre Belloni
488ae82d97 tty/serial: atmel: remove cache when unnecessary
struct cache is only used in suspend/resume. Exclude it when PM is not
selected.

Suggested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Alexandre Belloni
432f974801 tty/serial: atmel: increase ATMEL_MAX_UART
The samx7 family uses the same UART/USART IP as the at91/sama5 families but
has 8 of those.

Suggested-by: Szemző András <sza@esh.hu>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Takatoshi Akiyama
3c9101766b serial: sh-sci: Fix panic when serial console and DMA are enabled
This patch fixes an issue that kernel panic happens when DMA is enabled
and we press enter key while the kernel booting on the serial console.

* An interrupt may occur after sci_request_irq().
* DMA transfer area is initialized by setup_timer() in sci_request_dma()
  and used in interrupt.

If an interrupt occurred between sci_request_irq() and setup_timer() in
sci_request_dma(), DMA transfer area has not been initialized yet.
So, this patch changes the order of sci_request_irq() and
sci_request_dma().

Fixes: 73a19e4c03 ("serial: sh-sci: Add DMA support.")
Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
[Shimoda changes the commit log]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
Aleksey Makarov
713b93f1b8 Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
The original patch makes the condition always true, so it is wrong.

It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.

s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.

This reverts commit aea9a80ba9.

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:59:04 +08:00
James Hogan
b15bfbe642 serial: 8250_dw: Fix breakage when HAVE_CLK=n
Commit 6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be
used") recently broke the 8250_dw driver on platforms which don't select
HAVE_CLK, as dw8250_set_termios() gets confused by the behaviour of the
fallback HAVE_CLK=n clock API in linux/clk.h which pretends everything
is fine but returns (valid) NULL clocks and 0 HZ clock rates.

That 0 rate is written into the uartclk resulting in a crash at boot,
e.g. on Cavium Octeon III based UTM-8 we get something like this:

1180000000800.serial: ttyS0 at MMIO 0x1180000000800 (irq = 41, base_baud = 25000000) is a OCTEON
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1 at drivers/tty/serial/serial_core.c:441 uart_get_baud_rate+0xfc/0x1f0
...
Call Trace:
...
[<ffffffff8149c2e4>] uart_get_baud_rate+0xfc/0x1f0
[<ffffffff814a5098>] serial8250_do_set_termios+0xb0/0x440
[<ffffffff8149c710>] uart_set_options+0xe8/0x190
[<ffffffff814a6cdc>] serial8250_console_setup+0x84/0x158
[<ffffffff814a11ec>] univ8250_console_setup+0x54/0x70
[<ffffffff811901a0>] register_console+0x1c8/0x418
[<ffffffff8149f004>] uart_add_one_port+0x434/0x4b0
[<ffffffff814a1af8>] serial8250_register_8250_port+0x2d8/0x440
[<ffffffff814aa620>] dw8250_probe+0x388/0x5e8
...

The clock API is defined such that NULL is a valid clock handle so it
wouldn't be right to check explicitly for NULL. Instead treat a
clk_round_rate() return value of 0 as an error which prevents uartclk
being overwritten.

Fixes: 6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be used")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-serial@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jason Uy <jason.uy@broadcom.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:48:11 +08:00
Heiko Stuebner
09498087f9 serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
clk_round_rate returns a signed long and may possibly return errors
in it, for example if there is no possible rate.

Till now dw8250_set_termios ignored any error, the signednes and would
just use the value as input to clk_set_rate. This of course falls apart
if there is an actual error, so check for errors and only try to set
a rate if the value is actually valid.

This turned up on some Rockchip platforms after commit
6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be used")
enabled set_termios callback in all cases, not only ACPI.

Fixes: 6a171b2993 ("serial: 8250_dw: Allow hardware flow control to be used")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-14 10:48:11 +08:00
Krzysztof Kozlowski
f98c7bce57 serial: samsung: Continue to work if DMA request fails
If DMA is not available (even when configured in DeviceTree), the driver
will fail the startup procedure thus making serial console not
available.

For example this causes boot failure on QEMU ARMv7 (Exynos4210, SMDKC210):
    [    1.302575] OF: amba_device_add() failed (-19) for /amba/pdma@12680000
    ...
    [   11.435732] samsung-uart 13800000.serial: DMA request failed
    [   72.963893] samsung-uart 13800000.serial: DMA request failed
    [   73.143361] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000

DMA is not necessary for serial to work, so continue with UART startup
after emitting a warning.

Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-07 19:58:37 +01:00
Alexander Popov
82f2341c94 tty: n_hdlc: get rid of racy n_hdlc.tbuf
Currently N_HDLC line discipline uses a self-made singly linked list for
data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after
an error.

The commit be10eb7589
("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf.
After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put
one data buffer to tx_free_buf_list twice. That causes double free in
n_hdlc_release().

Let's use standard kernel linked list and get rid of n_hdlc.tbuf:
in case of tx error put current data buffer after the head of tx_buf_list.

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-07 18:54:30 +01:00
Ingo Molnar
0881e7bd34 sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h>
But first update usage sites with the new header dependency.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:40 +01:00
Ingo Molnar
299300258d sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:35 +01:00
Ingo Molnar
b17b01533b sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:34 +01:00
Ingo Molnar
174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Ingo Molnar
3f07c01441 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:29 +01:00
Ingo Molnar
ae7e81c077 sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h>
We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.

Create empty placeholder header that maps to <linux/types.h>.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:27 +01:00
Alexey Dobriyan
5b5e0928f7 lib/vsprintf.c: remove %Z support
Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.

Use BUILD_BUG_ON in a couple ATM drivers.

In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement.  Hopefully this patch inspires
someone else to trim vsprintf.c more.

Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:47 -08:00
Masahiro Yamada
3f8b6fb7f2 scripts/spelling.txt: add "comsume(r)" pattern and fix typo instances
Fix typos and add the following to the scripts/spelling.txt:

  comsume||consume
  comsumer||consumer
  comsuming||consuming

I see some variable names with this pattern, but this commit is only
touching comment blocks to avoid unexpected impact.

Link: http://lkml.kernel.org/r/1481573103-11329-19-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:47 -08:00
Vijay Kumar
7db60d05e5 sparc64: Send break twice from console to return to boot prom
Now we can also jump to boot prom from sunhv console by sending
break twice on console for both running and panicked kernel
cases.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-23 08:27:24 -08:00
Vijay Kumar
7dd4fcf5b7 sparc64: Migrate hvcons irq to panicked cpu
On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-23 08:27:24 -08:00
Michal Hocko
9af744d743 lib/show_mem.c: teach show_mem to work with the given nodemask
show_mem() allows to filter out node specific data which is irrelevant
to the allocation request via SHOW_MEM_FILTER_NODES.  The filtering is
done in skip_free_areas_node which skips all nodes which are not in the
mems_allowed of the current process.  This works most of the time as
expected because the nodemask shouldn't be outside of the allocating
task but there are some exceptions.  E.g.  memory hotplug might want to
request allocations from outside of the allowed nodes (see
new_node_page).

Get rid of this hardcoded behavior and push the allocation mask down the
show_mem path and use it instead of cpuset_current_mems_allowed.  NULL
nodemask is interpreted as cpuset_current_mems_allowed.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170117091543.25850-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22 16:41:30 -08:00
Linus Torvalds
37c85961c3 TTY/Serial driver patches for 4.11-rc1
Here is the big tty/serial driver patchset for 4.11-rc1.
 
 Not much here, but a lot of little fixes and individual serial driver
 updates all over the subsystem.  Majority are for the sh-sci driver and
 platform (the arch-specific changes have acks from the maintainer).
 
 The start of the "serial bus" code is here as well, but nothing is
 converted to use it yet.  That work is still ongoing, hopefully will
 start to show up across different subsystems for 4.12 (bluetooth is one
 major place that will be used.)
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big tty/serial driver patchset for 4.11-rc1.

  Not much here, but a lot of little fixes and individual serial driver
  updates all over the subsystem. Majority are for the sh-sci driver and
  platform (the arch-specific changes have acks from the maintainer).

  The start of the "serial bus" code is here as well, but nothing is
  converted to use it yet. That work is still ongoing, hopefully will
  start to show up across different subsystems for 4.12 (bluetooth is
  one major place that will be used.)

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (109 commits)
  tty: pl011: Work around QDF2400 E44 stuck BUSY bit
  atmel_serial: Use the fractional divider when possible
  tty: Remove extra include in HVC console tty framework
  serial: exar: Enable MSI support
  serial: exar: Move register defines from uapi header to consumer site
  serial: pci: Remove unused pci_boards entries
  serial: exar: Move Commtech adapters to 8250_exar as well
  serial: exar: Fix feature control register constants
  serial: exar: Fix initialization of EXAR registers for ports > 0
  serial: exar: Fix mapping of port I/O resources
  serial: sh-sci: fix hardware RX trigger level setting
  tty/serial: atmel: ensure state is restored after suspending
  serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt
  serdev: ttyport: check whether tty_init_dev() fails
  serial: 8250_pci: make pciserial_detach_ports() static
  ARM: dts: STiH410-b2260: Enable HW flow-control
  ARM: dts: STiH407-family: Use new Pinctrl groups
  ARM: dts: STiH407-pinctrl: Add Pinctrl group for HW flow-control
  ARM: dts: STiH410-b2260: Identify the UART RTS line
  dt-bindings: serial: Update 'uart-has-rtscts' description
  ...
2017-02-22 12:17:25 -08:00
Linus Torvalds
42e1b14b6e Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Implement wraparound-safe refcount_t and kref_t types based on
     generic atomic primitives (Peter Zijlstra)

   - Improve and fix the ww_mutex code (Nicolai Hähnle)

   - Add self-tests to the ww_mutex code (Chris Wilson)

   - Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr
     Bueso)

   - Micro-optimize the current-task logic all around the core kernel
     (Davidlohr Bueso)

   - Tidy up after recent optimizations: remove stale code and APIs,
     clean up the code (Waiman Long)

   - ... plus misc fixes, updates and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
  fork: Fix task_struct alignment
  locking/spinlock/debug: Remove spinlock lockup detection code
  lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS
  lkdtm: Convert to refcount_t testing
  kref: Implement 'struct kref' using refcount_t
  refcount_t: Introduce a special purpose refcount type
  sched/wake_q: Clarify queue reinit comment
  sched/wait, rcuwait: Fix typo in comment
  locking/mutex: Fix lockdep_assert_held() fail
  locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock()
  locking/rwsem: Reinit wake_q after use
  locking/rwsem: Remove unnecessary atomic_long_t casts
  jump_labels: Move header guard #endif down where it belongs
  locking/atomic, kref: Implement kref_put_lock()
  locking/ww_mutex: Turn off __must_check for now
  locking/atomic, kref: Avoid more abuse
  locking/atomic, kref: Use kref_get_unless_zero() more
  locking/atomic, kref: Kill kref_sub()
  locking/atomic, kref: Add kref_read()
  locking/atomic, kref: Add KREF_INIT()
  ...
2017-02-20 13:23:30 -08:00
Christopher Covington
d8a4995bce tty: pl011: Work around QDF2400 E44 stuck BUSY bit
The Qualcomm Datacenter Technologies QDF2400 family of SoCs contains a
custom (non-PrimeCell) implementation of the SBSA UART. Occasionally the
BUSY bit in the Flag Register gets stuck as 1, erratum 44 for both 2432v1
and 2400v1 SoCs.Checking that the Transmit FIFO Empty (TXFE) bit is 0,
instead of checking that the BUSY bit is 1, works around the issue.

To facilitate this substitution of flags and values, introduce
vendor-specific inversion of Feature Register bits when UART AMBA Port
(UAP) data is available. For the earlycon case, prior to UAP availability,
implement alternative putc and early_write functions.

Similar to what how ARMv8 ACPI PCI quirks are detected during MCFG parsing,
check the OEM fields of the Serial Port Console Redirection (SPCR) ACPI
table to determine if the current platform is known to be affected by the
erratum.

Signed-off-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Timur Tabi <timur@codeaurora.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-15 14:46:43 -08:00
Romain Izard
2867af2dcf atmel_serial: Use the fractional divider when possible
The fractional baud rate generator is available when using the
asynchronous mode of Atmel USART controllers. It makes it possible to
use higher baudrates, in exchange for a less precise clock with a
variable duty cycle.

The existing code restricts its use to the normal mode of the USART
controller, following the recommendation from the datasheet for the
first chip embedding this type of controller. This recommendation has
been removed from the documentation for the newer chips. After
verification, all revisions of this controller should be able to use the
fractional baud rate generator with the different asynchronous modes.

Removing the condition on ATMEL_US_USMODE makes it possible to get
correct baudrates at high speed in more cases.

This was tested with a board using an Atmel SAMA5D2 chip and a TI
WL1831 WiFi/Bluetooth combo chip at 3 Mbauds, with hardware flow control
enabled.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-14 10:12:21 -08:00
Sergio Valverde
6d35b131ca tty: Remove extra include in HVC console tty framework
An extra "init.h" include is found in the HVC console code. As such,
the extra line is deleted.

Signed-off-by: Sergio Valverde <vlvrdv@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 16:01:45 +01:00
Jan Kiszka
172c33cb61 serial: exar: Enable MSI support
Use pci_alloc_irq_vectors to enable MSI when available. At least the
XR17V352 supports this.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:13:26 +01:00
Jan Kiszka
7e12357ed6 serial: exar: Move register defines from uapi header to consumer site
None of these registers is relevant for the userspace API.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:13:26 +01:00
Jan Kiszka
0d560a1d54 serial: pci: Remove unused pci_boards entries
Became obsolete with the split-out of 8250_exar.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:12:39 +01:00
Jan Kiszka
fc6cc96157 serial: exar: Move Commtech adapters to 8250_exar as well
Those are Exar-based, too.

With the required refactoring of the code to fit into 8250_exar, we
automatically fix the same issue pci_xr17v35x_setup had before: 8XMODE,
FCTL, TXTRG and RXTRG were always only set for port 0. Now they are
initialized for the correct target port by using port.membase.

Now we can also cleanly fix the blacklist of 8250_pci so that all
Commtech devices are rejected and 8250_exar can handle them.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:12:38 +01:00
Jan Kiszka
5b5f252d67 serial: exar: Fix initialization of EXAR registers for ports > 0
So far, pci_xr17v35x_setup always initialized 8XMODE, FCTR & Co. for
port 0 because it used the address of that port instead of moving the
pointer according to the port number. Fix this and remove the unneeded
temporary ioremap by moving default_setup up and reusing the membase it
fills into the port structure.

Fixes: 14faa8cce8 ("tty/8250 Add support for Commtech's Fastcom Async-335 and Fastcom Async-PCIe cards")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:12:38 +01:00
Jan Kiszka
24572af4fb serial: exar: Fix mapping of port I/O resources
pcim_iomap_table only returns the table of mapping, it does not perform
them. For that, we need to call pcim_iomap, but only if that mapping was
not done before.

Fixes: d0aeaa83f0 ("serial: exar: split out the exar code from 8250_pci")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:12:38 +01:00
Ulrich Hecht
90afa5255f serial: sh-sci: fix hardware RX trigger level setting
1. Do not set the RX trigger level for software timeout devices on reset;
there is no timeout by default, and data will rot.
2. Do set the RX trigger level for hardware timeout devices when set
via sysfs attribute.

Fixes SCIFA-type serial consoles.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:10:16 +01:00
Alexandre Belloni
6a5f0e2f93 tty/serial: atmel: ensure state is restored after suspending
When going to suspend, the UART registers may be lost because the power to
VDDcore is cut. This is not an issue in the normal case but when
no_console_suspend is used, we need to restore the registers in order to
get a functional console.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:10:16 +01:00
Douglas Anderson
424d79183a serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt
On a Rockchip rk3399-based board during suspend/resume testing, we
found that we could get the console UART into a state where it would
print this to the console a lot:
  serial8250: too much work for irq42

Followed eventually by:
  NMI watchdog: BUG: soft lockup - CPU#0 stuck for 11s!

Upon debugging I found that we're in this state:
  iir = 0x000000cc
  lsr = 0x00000060

It appears that somehow we have a RX Timeout interrupt but there is no
actual data present to receive.  When we're in this state the UART
driver claims that it handled the interrupt but it actually doesn't
really do anything.  This means that we keep getting the interrupt
over and over again.

Normally we don't actually need to do anything special to handle a RX
Timeout interrupt.  We'll notice that there is some data ready and
we'll read it, which will end up clearing the RX Timeout.  In this
case we have a problem specifically because we got the RX TImeout
without any data.  Reading a bogus byte is confirmed to get us out of
this state.

It's unclear how exactly the UART got into this state, but it is known
that the UART lines are essentially undriven and unpowered during
suspend, so possibly during resume some garbage / half transmitted
bits are seen on the line and put the UART into this state.

The UART on the rk3399 is a DesignWare based 8250 UART.  From mailing
list posts, it appears that other people have run into similar
problems with DesignWare based IP.  Presumably this problem is unique
to that IP, so I have placed the workaround there to avoid possibly of
accidentally triggering bad behavior on other IP.  Also note the RX
Timeout behaves very differently in the DMA case, for for now the
workaround is only applied to the non-DMA case.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:10:16 +01:00