Although same 8250 compliant UART IP is reused across different SoC,
their integration wrt DMA varies greatly across SoCs. Therefore,
different SoC may need to use different FIFO trigger level for DMA
event and DMA configuration parameters. Provide a way to pass this
information via driver data. This is required to support UART DMA on
AM654/J721e SoCs.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200319110344.21348-5-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Terminate and flush DMA internal buffers, before pushing RX data to
higher layer. Otherwise, this will lead to data corruption, as driver
would end up pushing stale buffer data to higher layer while actual data
is still stuck inside DMA hardware and has yet not arrived at the
memory.
While at that, replace deprecated dmaengine_terminate_all() with
dmaengine_terminate_async().
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200319110344.21348-2-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When port's throttle callback is called, it should stop pushing any more
data into TTY buffer to avoid buffer overflow. This means driver has to
stop HW from receiving more data and assert the HW flow control. For
UARTs with auto HW flow control (such as 8250_omap) manual assertion of
flow control line is not possible and only way is to allow RX FIFO to
fill up, thus trigger auto HW flow control logic.
Therefore make sure that 8250 generic IRQ handler does not drain data
when port is stopped (i.e UART_LSR_DR is unset in read_status_mask). Not
servicing, RX FIFO would trigger auto HW flow control when FIFO
occupancy reaches preset threshold, thus halting RX.
Since, error conditions in UART_LSR register are cleared just by reading
the register, data has to be drained in case there are FIFO errors, else
error information will lost.
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200319103230.16867-2-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 7765435030 ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
checking for the presence of the ->set_serial function pointer rather
than ->get_serial. This appears to be a copy-and-paste error, since
->get_serial is the function pointer that is called as well as the
pointer that is checked by the non-compat version of TIOCGSERIAL.
Fix this by checking the correct function pointer.
Fixes: 7765435030 ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200224182044.234553-3-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().
Also rewrite the code in a standard if-form instead of ugly
conditional operators.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200311092905.24362-1-tiwai@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch simplifies the process of getting serial port number, with
this patch, serial devices must have aliases configured in devicetree.
The serial port searched out via sprd_port array maybe wrong if we don't
have serial alias defined in devicetree, and specify console with command
line, we would get the wrong port number if other serial ports probe
failed before console's. So using aliases is mandatory.
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20200318105049.19623-2-zhang.lyra@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It would be too tricky and error prone to allow DMA operations on
kernel console.
One of the concern is when DMA is a separate device, for example on
Intel CherryTrail platforms, and might need special work around to be
functional, see the commit
eebb3e8d8a ("ACPI / LPSS: override power state for LPSS DMA device")
for more information.
Another one is that kernel console is used in atomic context, e.g.
when printing crucial information to the user (Oops or crash),
and DMA may not serve due to power management complications
including non-atomic ACPI calls but not limited to it (see above).
Besides that, other concerns are described in the commit
84b40e3b57 ("serial: 8250: omap: Disable DMA for console UART")
done for OMAP UART and may be repeated here.
Disable any kind of DMA operations on kernel console due to above concerns.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200217114016.49856-7-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Doing any kind of power management for kernel console is really bad idea.
First of all, it runs in poll and atomic mode. This fact attaches a limitation
on the functions that might be called. For example, pm_runtime_get_sync() might
sleep and thus can't be used. This call needs, for example, to bring the device
to powered on state on the system, where the power on sequence may require
on-atomic operations, such as Intel Cherrytrail with ACPI enumerated UARTs.
That said, on ACPI enabled platforms it might even call firmware for a job.
On the other hand pm_runtime_get() doesn't guarantee that device will become
powered on fast enough.
Besides that, imagine the case when console is about to print a kernel Oops and
it's powered off. In such an emergency case calling the complex functions is
not the best what we can do, taking into consideration that user wants to see
at least something of the last kernel word before it passes away.
Here we modify the 8250 console code to prevent runtime power management.
Note, there is a behaviour change for OMAP boards. It will require to detach
kernel console to become idle.
Link: https://lists.openwall.net/linux-kernel/2018/09/29/65
Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200217114016.49856-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ev_byte_channel_send() assumes that its third argument is a 16 byte
array. Some places where it is called it may not be (or we can't
easily tell if it is). Newer compilers have started producing warnings
about this, so make sure we actually pass a 16 byte array.
There may be more elegant solutions to this, but the driver is quite
old and hasn't been updated in many years.
The warnings (from a powerpc allyesconfig build) are:
In file included from include/linux/byteorder/big_endian.h:5,
from arch/powerpc/include/uapi/asm/byteorder.h:14,
from include/asm-generic/bitops/le.h:6,
from arch/powerpc/include/asm/bitops.h:250,
from include/linux/bitops.h:29,
from include/linux/kernel.h:12,
from include/asm-generic/bug.h:19,
from arch/powerpc/include/asm/bug.h:109,
from include/linux/bug.h:5,
from include/linux/mmdebug.h:5,
from include/linux/gfp.h:5,
from include/linux/slab.h:15,
from drivers/tty/ehv_bytechan.c:24:
drivers/tty/ehv_bytechan.c: In function ‘ehv_bc_udbg_putc’:
arch/powerpc/include/asm/epapr_hcalls.h:298:20: warning: array subscript 1 is outside array bounds of ‘const char[1]’ [-Warray-bounds]
298 | r6 = be32_to_cpu(p[1]);
include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’
40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x))
| ^
arch/powerpc/include/asm/epapr_hcalls.h:298:7: note: in expansion of macro ‘be32_to_cpu’
298 | r6 = be32_to_cpu(p[1]);
| ^~~~~~~~~~~
drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’
166 | static void ehv_bc_udbg_putc(char c)
| ^~~~~~~~~~~~~~~~
Fixes: dcd83aaff1 ("tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
[mpe: Trim warnings from change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200109183912.5fcb52aa@canb.auug.org.au
The geni serial driver's shutdown code had a special case to call
console_stop(). Grepping through the code, it was the only serial
driver doing something like this (the only other caller of
console_stop() was in serial_core.c).
As far as I can tell there's no reason to call console_stop() in the
geni code. ...and a good reason _not_ to call it. Specifically if
you have an agetty running on the same serial port as the console then
killing the agetty kills your console and if you start the agetty
again the console doesn't come back.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200313134635.2.I3648fac6c98b887742934146ac2729ecb7232eb1@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a board using qcom_geni_serial I found that I could no longer
interact with kdb if I got a crash after the "agetty" running on the
same serial port was killed. This meant that various classes of
crashes that happened at reboot time were undebuggable.
Reading through the code, I couldn't figure out why qcom_geni_serial
felt the need to run so much code at port shutdown time. All we need
to do is disable the interrupt.
After I make this change then a hardcoded kgdb_breakpoint in some late
shutdown code now allows me to interact with the debugger. I also
could freely close / re-open the port without problems.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200313134635.1.Icf54c533065306b02b880c46dfd401d8db34e213@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The vc_cons_allocated() checks in vt_ioctl() and vt_compat_ioctl() are
unnecessary because they can only be reached by calling ioctl() on an
open tty, which implies the corresponding virtual console is allocated.
And even if the virtual console *could* be freed concurrently, then
these checks would be broken since they aren't done under console_lock,
and the vc_data is dereferenced before them anyway.
So, remove these unneeded checks to avoid confusion.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200224080326.295046-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move LDISC_AUTOLOAD ahead of the Serial drivers menu.
Move the Serial drivers menu ahead of the Non-standard serial port
support menu.
Move NOZOMI out of the SERIAL_NONSTANDARD area since it does not
depend on SERIAL_NONSTANDARD and it breaks the SERIAL_NONSTANDARD
menu list.
Alphabetize the remaining drivers (in tty/Kconfig) by their prompt strings.
[The drivers in tty/hvc/Kconfig and tty/serial/Kconfig have not
been alphabetized.]
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200311225736.32147-4-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Refactor uart_unlock_and_check_sysrq() to:
- explicitly show that we release a port lock which makes
static analyzers happy:
CHECK drivers/tty/serial/serial_core.c
.../serial_core.c:3290:17: warning: context imbalance in 'uart_unlock_and_check_sysrq' - unexpected unlock
- use flags instead of irqflags to avoid confusion with IRQ flags
- provide one return point
- be more compact
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20200310174337.74109-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Compiler is not happy about using ARRAY_SIZE() in comparison to smaller type:
CC drivers/tty/serial/serial_core.o
.../serial_core.c: In function ‘uart_try_toggle_sysrq’:
.../serial_core.c:3222:24: warning: comparison is always false due to limited range of data type [-Wtype-limits]
3222 | if (++port->sysrq_seq < (ARRAY_SIZE(sysrq_toggle_seq) - 1)) {
| ^
Looking at the code it appears that there is an additional weirdness,
i.e. use ARRAY_SIZE() against simple string literal. Yes, the idea probably
was to allow '\0' in the sequence, but it's impractical: kernel configuration
won't accept it to begin with followed by a comment about '\0' before
comparison in question.
Drop all these by switching to strlen() and convert code accordingly.
Note, GCC seems clever enough to calculate string length at compile time.
Fixes: 68af43173d ("serial/sysrq: Add MAGIC_SYSRQ_SERIAL_SEQUENCE")
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200310174337.74109-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To fix the RX cancel command failure, rx_fifo buffer needs to be
flushed in stop_rx() by calling handle_rx().In handle_rx() the data
in rx_fifo buffer is read and then dropped, not sent to upper layers.
If set_termios is called before startup, by this time memory is not
allocated to port->rx_fifo buffer, which leads to a NULL pointer
dereference.
To avoid this NULL pointer dereference allocate memory to port->rx_fifo
in probe itself.
Signed-off-by: satya priya <skakit@codeaurora.org>
Reported-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1583477228-32231-2-git-send-email-skakit@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver for the Intel MID never seems to have been properly
integrated upstream: the platform data in <linux/spi/ifx_modem.h>
is not used anywhere in the kernel and haven't been since it was
merged into the kernel in 2010.
There might be out-of-tree users, so I don't want to delete the
driver, but I will refactor it to use GPIO descriptors, which
means that out-of-tree users will need to adapt.
There are several examples in the kernel of how to provide the
resources necessary for using GPIO descriptors to pass in the
GPIO lines, for the MID platform in particular, it will suffice
to inspect the code in files like:
arch/x86/platform/intel-mid/device_libs/platform_bt.c
This refactoring transfers all GPIOs in the driver, including
a hard-coded "PMU reset" in the driver to use GPIO descriptors
instead.
The following named GPIO descriptors need to be supplied:
- reset
- power
- mrdy
- srdy
- rst_out
- pmu_reset
Cc: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200311083131.693908-2-linus.walleij@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
