Commit Graph

18 Commits

Author SHA1 Message Date
Andy Shevchenko
b1261c86fe serial: 8250: introduce up_to_u8250p() helper
It helps to cast struct uart_port to struct uart_8250_port at runtime.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:16:23 -07:00
Peter Hurley
ef8b9ddcb4 serial: Fix IGNBRK handling
If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: Ivan <athlon_@mail.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19 13:04:52 -07:00
Linus Torvalds
49eb7b0750 TTY/Serial driver patches for 3.16-rc1
Here is the big tty / serial driver pull request for 3.16-rc1.
 
 A variety of different serial driver fixes and updates and additions,
 nothing huge, and no real major core tty changes at all.
 
 All have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty into next

Pull tty/serial driver updates from Greg KH:
 "Here is the big tty / serial driver pull request for 3.16-rc1.

  A variety of different serial driver fixes and updates and additions,
  nothing huge, and no real major core tty changes at all.

  All have been in linux-next for a while"

* tag 'tty-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
  Revert "serial: imx: remove the DMA wait queue"
  serial: kgdb_nmi: Improve console integration with KDB I/O
  serial: kgdb_nmi: Switch from tasklets to real timers
  serial: kgdb_nmi: Use container_of() to locate private data
  serial: cpm_uart: No LF conversion in put_poll_char()
  serial: sirf: Fix compilation failure
  console: Remove superfluous readonly check
  console: Use explicit pointer type for vc_uni_pagedir* fields
  vgacon: Fix & cleanup refcounting
  ARM: tty: Move HVC DCC assembly to arch/arm
  tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick()
  drivers/tty/n_hdlc.c: replace kmalloc/memset by kzalloc
  vt: emulate 8- and 24-bit colour codes.
  printk/of_serial: fix serial console cessation part way through boot.
  serial: 8250_dma: check the result of TX buffer mapping
  serial: uart: add hw flow control support configuration
  tty/serial: at91: add interrupts for modem control lines
  tty/serial: at91: use mctrl_gpio helpers
  tty/serial: Add GPIOLIB helpers for controlling modem lines
  ARM: at91: gpio: implement get_direction
  ...
2014-06-03 09:01:02 -07:00
Murali Karicheri
06aa82e498 serial: uart: add hw flow control support configuration
8250 uart driver currently supports only software assisted hw flow
control. The software assisted hw flow control maintains a hw_stopped
flag in the tty structure to stop and start transmission and use modem
status interrupt for the event to drive the handshake signals. This is
not needed if hw has flow control capabilities. This patch adds a
DT attribute for enabling hw flow control for a uart port. Also skip
stop and start if this flag is present in flag field of the port
structure.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>
CC: Randy Dunlap <rdunlap@infradead.org>
CC: Jiri Slaby <jslaby@suse.cz>
CC: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 13:04:46 -07:00
Michael Welling
b790f210fe tty: serial: 8250_core.c Bug fix for Exar chips.
The sleep function was updated to put the serial port to sleep only when necessary.
This appears to resolve the errant behavior of the driver as described in
Kernel Bug 61961 – "My Exar Corp. XR17C/D152 Dual PCI UART modem does not
work with 3.8.0".

Signed-off-by: Michael Welling <mwelling@ieee.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-03 18:13:05 -04:00
Greg Kroah-Hartman
f379a07109 Merge 3.15-rc3 into tty-next 2014-04-27 21:40:39 -07:00
Doug Anderson
c7d44a02ac serial_core: Commonalize crlf when working w/ a non open console port
In (efe2f29 kgdboc,kdb: Allow kdb to work on a non open console port)
support was added to directly use the "write_char" functions when
doing kdb over a non-open console port.  This is great, but it ends up
bypassing the normal code in uart_console_write() that adds a carriage
return before any newlines.

There appears to have been a trend to add this support directly in
some console driver's poll_put_char() functions.  This had a few side
effects, including:
- In this case we were doing LFCR, not CRLF.  This was fixed in
  uart_console_write() back in (d358788 [SERIAL] kernel console should
  send CRLF not LFCR)
- Not all serial drivers had the LFCR code in their poll_put_char()
  functions.  In my case I was running serial/samsung.c which lacked
  it.

I've moved the handling to uart_poll_put_char() to fix the above
problems.  Now when I use kdb (and don't point console= to the same
UART) I no longer get:

[0]kdb>
       [0]kdb>
              [0]kdb>

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:13:01 -07:00
Loic Poulain
b08c9c317e 8250_core: Fix unwanted TX chars write
On transmit-hold-register empty, serial8250_tx_chars
should be called only if we don't use DMA.
DMA has its own tx cycle.

Signed-off-by: Loic Poulain <loic.poulain@intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 15:18:02 -07:00
Ingo Molnar
ebade5e833 serial: 8250: Clean up the locking for -rt
In -RT the spin_lock_irqsave() does not spin but sleep if the lock is
taken. Before that, local_irq_save() is invoked which disables
interrupts even on -RT. Therefore local_irq_save() + spin_lock() does not
work.
In the ->sysrq and oops_in_progress case it is save to trylock the lock
i.e. this is what we do now anyway except for ->sysrq where we assume
that the lock is already taken.

The spin_lock_irqsave() grabs the lock and disables the interrupts on
vanilla (the same behavior) and on -RT it won't disable interrupts.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: add a patch description]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:24:53 -08:00
Paul Gortmaker
bd2fe272a8 drivers/tty/serial: deal with 8250_core.c uninitialized warning for good
Every couple of months, someone sends a patch to fix:

drivers/tty/serial/8250/8250_core.c: In function 'serial_unlink_irq_chain':
drivers/tty/serial/8250/8250_core.c:1712:2: warning: 'i' may be used uninitialized in this function [-Wuninitialized]

and they in turn get a NACK for their efforts, and are told that
their compiler is broken.  This has been going on since at least
the year 2008:  https://lkml.org/lkml/2008/11/24/433

Lets add a comment, so that subsequent patches don't get as far as
the maintainers or the mailing lists.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:25:47 -08:00
Joe Schultz
45a7bd6359 serial: 8250: Support XR17V35x fraction divisor
The Exar XR17V35x family of UARTs have an additional fractional divisor
register (DLD) which was not being used. Calculate and set this
register for these devices to reduce their baud rate error.

Signed-off-by: Joe Schultz <jschultz@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Stephen Warren
3685f19e07 serial: 8250: enable UART_BUG_NOMSR for Tegra
Tegra chips have 4 or 5 identical UART modules embedded. UARTs C..E have
their MODEM-control signals tied off to a static state. However UARTs A
and B can optionally route those signals to/from package pins, depending
on the exact pinmux configuration.

When these signals are not routed to package pins, false interrupts may
trigger either temporarily, or permanently, all while not showing up in
the IIR; it will read as NO_INT. This will eventually lead to the UART
IRQ being disabled due to unhandled interrupts. When this happens, the
kernel may print e.g.:

    irq 68: nobody cared (try booting with the "irqpoll" option)

In order to prevent this, enable UART_BUG_NOMSR. This prevents
UART_IER_MSI from being enabled, which prevents the false interrupts
from triggering.

In practice, this is not needed under any of the following conditions:

* On Tegra chips after Tegra30, since the HW bug has apparently been
  fixed.

* On UARTs C..E since their MODEM control signals are tied to the correct
  static state which doesn't trigger the issue.

* On UARTs A..B if the MODEM control signals are routed out to package
  pins, since they will then carry valid signals.

However, we ignore these exceptions for now, since they are only relevant
if a board actually hooks up more than a 4-wire UART, and no currently
supported board does this. If we ever support a board that does, we can
refine the algorithm that enables UART_BUG_NOMSR to take those exceptions
into account, and/or read a flag from DT/... that indicates that the
board has hooked up and pinmux'd more than a 4-wire UART.

Reported-by: Olof Johansson <olof@lixom.net> # autotester
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-07 17:14:24 -08:00
Heikki Krogerus
2797f6fb67 serial: 8250: don't change the fifo trigger level when using dma
DMA engines usually expect the fifo trigger level to be
aligned with the burst size. It should not be changed even
with small baud rates. This will fix an issue with
Designware DMA engine where the data can not be transferred
over UART with lower baud rates then 2400.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 14:27:24 -07:00
Jingoo Han
574de559c1 serial: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-31 17:56:15 -07:00
Kyle McMartin
317a68427d Revert "serial: 8250: Make SERIAL_8250_RUNTIME_UARTS work correctly"
This reverts commit cfcec52e97.

This regresses a longstanding behaviour on X86 systems, which end up with
PCI serial ports moving between ttyS4 and ttyS0 when you bisect to opposite
sides of this commit, resulting in the need to constantly modify the console
setting in order to bisect across it.

Please revert, we can work on solving this for ARM platforms in a less
disruptive way.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Karthik Manamcheri <karthik.manamcheri@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 10:08:28 -07:00
Greg Kroah-Hartman
ef99f3aee9 Merge 3.9-rc5 into tty-next
We need the fixes here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-01 12:01:10 -07:00
Jiri Slaby
9326b047e4 TTY: 8250, deprecated 8250_core.* options
They were introduced by mistake in 3.7. Let's deprecate them now. For
the reasons, see the text in Kconfig below.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-25 16:26:23 -07:00
Jiri Slaby
9196d8acd7 TTY: 8250, revert module name change
In 3.7 the 8250 module name was changed unintentionally from 8250 to
8250_core by commit 835d844d1a
(8250_pnp: do pnp probe before legacy probe). We then had to
re-introduce the old module options to ensure the old good
8250.nr_uart & co. still work. This can be done only by a very dirty
hack and we did it in f2b8dfd9e4
(serial: 8250: Keep 8250.<xxxx> module options functional after driver
rename).

That is so damn ugly so that I decided to revert to the old module
name and deprecate the new 8250_core options present in 3.7 and 3.8
only. The deprecation will happen in the following patch.

Note that this patch changes the hack above to support "8250_core.*",
because we now have "8250.*" natively.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-25 16:26:23 -07:00