Add device attributes to display details about the connection status
of HVC IUCV terminals.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/tty/hvc/hvc_iucv.c:131:25: warning: symbol 'hvc_iucv_get_private' was not
declared. Should it be static?
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The uart timer will schedule a tasklet when it fires. It is possible that it
can fire inside _shutdown before it is killed in the dma and pdc cleanup
routines. This causes a tasklet that exists after the port is shutdown, so when
the kernel finally executes it, it panics as the tty port is NULL.
This is a somewhat rare condition but its possible if a program keeps on
opening/closing the port. It has been observed in particular with systemd
boot messages that were causing a kernel panic because of this behavior.
Moving the timer deletion to the beginning of the function stops a tasklet from
being scheduled unexpectedly.
Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Cc: stable <stable@vger.kernel.org> # v3.12
[nicolas.ferre@atmel.com: modify commit message, call setup_timer() in any case]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
When using RX DMA, the driver won't pass any data to the uart layer
until the buffer is flipped. When the port is shutdown, the dma buffers
are unmapped, but the head and tail of the ring buffer are not reseted.
Since the serial console will keep the port open, this will only
present itself when the uart is not shared.
To reproduce the issue, with an unpatched driver, run a getty on /dev/ttyS0
with no serial console and exit. Getty will exit, and when the new one returns
you will be unable to log in. If you hold down a key long enough to fill the
DMA buffer and flip it, you can then log in.
Signed-off-by: Mark Deneen <mdeneen@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
[nicolas.ferre@atmel.com: adapt to mainline kernel, handle !DMA case]
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The _remove callback could be called when a tasklet is scheduled. tasklet_kill
was called inside the function in order to free up any scheduled tasklets.
However it was called after uart_remove_one_port which destroys tty references
needed in the port for atmel_tasklet_func.
Simply putting the tasklet_kill at the start of the function will prevent this
conflict.
Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Interrupts were being cleaned up late in the shutdown handler, it is possible
that an interrupt can occur and schedule a tasklet that runs after the port is
cleaned up. There is a null dereference due to this race condition with the
following stacktrace:
[<c02092b0>] (atmel_tasklet_func+0x514/0x814) from [<c001fd34>] (tasklet_action+0x70/0xa8)
[<c001fd34>] (tasklet_action+0x70/0xa8) from [<c001f60c>] (__do_softirq+0x90/0x144)
[<c001f60c>] (__do_softirq+0x90/0x144) from [<c001fa18>] (irq_exit+0x40/0x4c)
[<c001fa18>] (irq_exit+0x40/0x4c) from [<c000e298>] (handle_IRQ+0x64/0x84)
[<c000e298>] (handle_IRQ+0x64/0x84) from [<c000d6c0>] (__irq_svc+0x40/0x50)
[<c000d6c0>] (__irq_svc+0x40/0x50) from [<c0208060>] (atmel_rx_dma_release+0x88/0xb8)
[<c0208060>] (atmel_rx_dma_release+0x88/0xb8) from [<c0209740>] (atmel_shutdown+0x104/0x160)
[<c0209740>] (atmel_shutdown+0x104/0x160) from [<c0205e8c>] (uart_port_shutdown+0x2c/0x38)
Signed-off-by: Marek Roszko <mark.roszko@gmail.com>
Acked-by: Leilei Zhao <leilei.zhao@atmel.com>
Cc: <stable@vger.kernel.org> # v3.12
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In rx dma-callback it calls tasklet_schedule, if the tasklet
be scheduled after all the dma-callback in the rx dma channel,
current check condition in the tasklet will not do fetch dma
buffer into tty because tx_issued is equal with tx_completed,
so as timeout tasklet does.
so we check whether we should fetch the whole dma buffer into
tty according to the status of transactions in rx dma channel.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
this patch provides PM entry of uart_ops, then drop clk enable and
disable because serial core will do it.
the patch also fixes the issue that uart hang in resume caused by
not-enabled clock.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
use SET_SYSTEM_SLEEP_PM_OPS to initialize suspend/resume functions
instead of legacy suspend and resume entries of platform_driver.
this will add hibernation support automatically as suspend to disk
entries are also set.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This helps increasing build testing coverage.
To do this, read{write}_relaxed() functions was be replaced with
simple read{write}() variants. Potential "uninitialized variable"
warnings was be fixed if driver compiled without MFD_SYSCON.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replace custom handling of IrDA feature with N_IRDA
line discipline, so IrDA mode can be used with irtty driver.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The four variants of the synclink driver use the same code in their
open() callback to wait for a port in process of being closed,
using interruptible_sleep_on, which is racy and going away soon.
Making things worse, these functions hold the BTM while doing so,
which means that if we ever enter this code path, we cannot actually
continue since the other thread that is in process of closing the
port can no longer get the BTM.
This addresses both issues by using wait_event_interruptible_tty()
instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
interruptible_sleep_on is generally problematic and we want to get
rid of it. In case of TIOCMIWAIT, that race is actually in user
space and does not get fixed since we can only detect changes after
entering the ioctl handler, but it removes one more caller.
This instance can not be trivially replaced with wait_event, so
I chose to open-code the wait loop using prepare_to_wait/finish_wait.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
there is an overflow in the code :
cyz_polling_cycle = (arg * HZ) / 1000,
the multiplicator arg comes from user, so it may be an overflow if
arg is a big number. And the value of cyc_polling_cycle will be
wrong when it is used next time.
Reported-by: Qixue Xiao <xiaoqixue_1@163.com>
Suggested-by: Yongjian Xu <xuyongjiande@gmail.com>
Suggested-by: Yu Chen <chyyuu@gmail.com>
Signed-off-by: Qixue Xiao <xiaoqixue_1@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
New driver for NXP (Philips) UART ICs was introduced in September 2012.
Old driver no longer used anywhere, this patch removes it.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the initialisation of older Quatech serial cards which are fitted with
the AMCC PCI Matchmaker interface chip.
Signed-off-by: Jonathan Woithe (jwoithe@just42.net)
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 'tty: xuartps: Implement BREAK detection, add SYSRQ support'
(0c0c47bc40) introduced sysrq support
without properly guarding sysrq specific code which results in build
errors when sysrq is disabled:
DNAME=KBUILD_STR(xilinx_uartps)" -c -o
drivers/tty/serial/.tmp_xilinx_uartps.o
drivers/tty/serial/xilinx_uartps.c
drivers/tty/serial/xilinx_uartps.c: In function 'xuartps_isr':
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
drivers/tty/serial/xilinx_uartps.c:247:5: error: 'struct uart_port'
has no member named 'sysrq'
make[3]: *** [drivers/tty/serial/xilinx_uartps.o] Error 1
Reported-by: Masanari Iida <standby24x7@gmail.com>
Cc: Vlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With block processing of echoed output, observed output order is still
required. Push completed echoes and echo commands prior to output.
Introduce echo_mark echo buffer index, which tracks completed echo
commands; ie., those submitted via commit_echoes but which may not
have been committed. Ensure that completed echoes are output prior
to subsequent terminal writes in process_echoes().
Fixes newline/prompt output order in cooked mode shell.
Cc: <stable@vger.kernel.org> # 3.12.x : 39434ab n_tty: Fix missing newline echo
Reported-by: Karl Dahlke <eklhad@comcast.net>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Karl Dahlke <eklhad@comcast.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newer Intel PCHs with LPSS have the same Designware controllers than
Haswell but ACPI IDs are different. Add these IDs to the driver list.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mark the function hvc_poll_init() as static in hvc/hvc_console.c because
it is not used outside this file.
This eliminates the following warning in hvc/hvc_console.c:
drivers/tty/hvc/hvc_console.c:791:5: warning: no previous prototype for ‘hvc_poll_init’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Marks the functions gsm_cleanup_mux(), gsm_activate_mux(),
gsm_free_mux(), gsm_alloc_mux() and gsm_change_mtu() as static in
n_gsm.c because they are not used outside this file.
Also, drop the EXPORT_SYMBOL_GPL for the above mentioned functions
because nothing else in the kernel calls them.
This eliminates the following warnings in n_gsm.c:
drivers/tty/n_gsm.c:2022:6: warning: no previous prototype for ‘gsm_cleanup_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2076:5: warning: no previous prototype for ‘gsm_activate_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2120:6: warning: no previous prototype for ‘gsm_free_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2156:17: warning: no previous prototype for ‘gsm_alloc_mux’ [-Wmissing-prototypes]
drivers/tty/n_gsm.c:2714:5: warning: no previous prototype for ‘gsm_change_mtu’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When falling back from DMA to interrupt mode the receive interrupt has to
be re-enabled to catch new incoming data.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In pl011_rx_chars() if pl011_dma_rx_trigger_dma() succeeds it will disable
the receive interrupt, no need to do this again.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During initialisation, a UART may already be in use for a console, so
take care to preserve things like baud rate and data format to avoid
corrupting console output.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code to cope with a split tx/rx LCR_H register is non-trivial
so put it into it's own function to avoid duplication.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the pl011 is being used for a console, pl011_console_write forces
the control register (CR) to enable the UART for transmission and then
restores this to the original value afterwards. It does this while
holding the port lock.
Unfortunately, when the uart is started or shutdown - say in response to
userland using the serial device for a terminal - then this updates the
control register without any locking.
This means we can have
pl011_console_write Save CR
pl011_startup Initialise CR, e.g. enable receive
pl011_console_write Restore old CR with receive not enabled
this result is a serial port which doesn't respond to any input.
A similar race in reverse could happen when the device is shutdown.
We can fix these problems by taking the port lock when updating CR.
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 17438217a6 on request
of Linus Walleij:
Greg can you please drop or revert
commit 17438217a6
"serial: pl011: use DMA RX polling by default"
from the TTY tree until this has been sorted out?
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
readline() inadvertently triggers an error recovery path when
pastes larger than 4k overrun the line discipline buffer. The
error recovery path discards input when the line discipline buffer
is full and operating in canonical mode and no newline has been
received. Because readline() changes the termios to non-canonical
mode to read the line char-by-char, the line discipline buffer
can become full, and then when readline() restores termios back
to canonical mode for the caller, the now-full line discipline
buffer triggers the error recovery.
When changing termios from non-canon to canon mode and the read
buffer contains data, simulate an EOF push _without_ the
DISABLED_CHAR in the read buffer.
Importantly for the readline() problem, the termios can be
changed back to non-canonical mode without changes to the read
buffer occurring; ie., as if the previous termios change had not
happened (as long as no intervening read took place).
Preserve existing userspace behavior which allows '\0's already
received in non-canon mode to be read as '\0's in canon mode
(rather than trigger add'l EOF pushes or an actual EOF).
Patch based on original proposal and discussion here
https://bugzilla.kernel.org/show_bug.cgi?id=55991
by Stas Sergeev <stsp@users.sourceforge.net>
Reported-by: Margarita Manterola <margamanterola@gmail.com>
Cc: Maximiliano Curia <maxy@gnuservers.com.ar>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Acked-by: Stas Sergeev <stsp@users.sourceforge.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a complex patch for refactoring CLPS711X serial driver.
Major changes:
- Eliminate <mach/hardware.h> usage.
- Devicetree support.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit c49436b657 (serial: 8250_dw: Improve unwritable LCR workaround)
caused a regression. It added a check that the LCR was written properly
to detect and workaround the busy quirk, but the behaviour of bit 5
(UART_LCR_SPAR) differs between IP versions 3.00a and 3.14c per the
docs. On older versions this caused the check to fail and it would
repeatedly force idle and rewrite the LCR register, causing delays and
preventing any input from serial being received.
This is fixed by masking out UART_LCR_SPAR before making the comparison.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Tim Kryger <tim.kryger@linaro.org>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: Matt Porter <matt.porter@linaro.org>
Cc: Markus Mayer <markus.mayer@linaro.org>
Tested-by: Tim Kryger <tim.kryger@linaro.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a controlling tty is being hung up and the hang up is
waiting for a just-signalled tty reader or writer to exit, and a new tty
reader/writer tries to acquire an ldisc reference concurrently with the
ldisc reference release from the signalled reader/writer, the hangup
can hang. The new reader/writer is sleeping in ldsem_down_read() and the
hangup is sleeping in ldsem_down_write() [1].
The new reader/writer fails to wakeup the waiting hangup because the
wrong lock count value is checked (the old lock count rather than the new
lock count) to see if the lock is unowned.
Change helper function to return the new lock count if the cmpxchg was
successful; document this behavior.
[1] edited dmesg log from reporter
SysRq : Show Blocked State
task PC stack pid father
systemd D ffff88040c4f0000 0 1 0 0x00000000
ffff88040c49fbe0 0000000000000046 ffff88040c4a0000 ffff88040c49ffd8
00000000001d3980 00000000001d3980 ffff88040c4a0000 ffff88040593d840
ffff88040c49fb40 ffffffff810a4cc0 0000000000000006 0000000000000023
Call Trace:
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff817a6649>] schedule+0x24/0x5e
[<ffffffff817a588b>] schedule_timeout+0x15b/0x1ec
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff817aa691>] ? _raw_spin_unlock_irq+0x24/0x26
[<ffffffff817aa10c>] down_read_failed+0xe3/0x1b9
[<ffffffff817aa26d>] ldsem_down_read+0x8b/0xa5
[<ffffffff8142b5ca>] ? tty_ldisc_ref_wait+0x1b/0x44
[<ffffffff8142b5ca>] tty_ldisc_ref_wait+0x1b/0x44
[<ffffffff81423f5b>] tty_write+0x7d/0x28a
[<ffffffff814241f5>] redirected_tty_write+0x8d/0x98
[<ffffffff81424168>] ? tty_write+0x28a/0x28a
[<ffffffff8115d03f>] do_loop_readv_writev+0x56/0x79
[<ffffffff8115e604>] do_readv_writev+0x1b0/0x1ff
[<ffffffff8116ea0b>] ? do_vfs_ioctl+0x32a/0x489
[<ffffffff81167d9d>] ? final_putname+0x1d/0x3a
[<ffffffff8115e6c7>] vfs_writev+0x2e/0x49
[<ffffffff8115e7d3>] SyS_writev+0x47/0xaa
[<ffffffff817ab822>] system_call_fastpath+0x16/0x1b
bash D ffffffff81c104c0 0 5469 5302 0x00000082
ffff8800cf817ac0 0000000000000046 ffff8804086b22a0 ffff8800cf817fd8
00000000001d3980 00000000001d3980 ffff8804086b22a0 ffff8800cf817a48
000000000000b9a0 ffff8800cf817a78 ffffffff81004675 ffff8800cf817a44
Call Trace:
[<ffffffff81004675>] ? dump_trace+0x165/0x29c
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff8100edda>] ? save_stack_trace+0x26/0x41
[<ffffffff817a6649>] schedule+0x24/0x5e
[<ffffffff817a588b>] schedule_timeout+0x15b/0x1ec
[<ffffffff810a4cc0>] ? sched_clock_cpu+0x9f/0xe4
[<ffffffff817a9f03>] ? down_write_failed+0xa3/0x1c9
[<ffffffff817aa691>] ? _raw_spin_unlock_irq+0x24/0x26
[<ffffffff817a9f0b>] down_write_failed+0xab/0x1c9
[<ffffffff817aa300>] ldsem_down_write+0x79/0xb1
[<ffffffff817aada3>] ? tty_ldisc_lock_pair_timeout+0xa5/0xd9
[<ffffffff817aada3>] tty_ldisc_lock_pair_timeout+0xa5/0xd9
[<ffffffff8142bf33>] tty_ldisc_hangup+0xc4/0x218
[<ffffffff81423ab3>] __tty_hangup+0x2e2/0x3ed
[<ffffffff81424a76>] disassociate_ctty+0x63/0x226
[<ffffffff81078aa7>] do_exit+0x79f/0xa11
[<ffffffff81086bdb>] ? get_signal_to_deliver+0x206/0x62f
[<ffffffff810b4bfb>] ? lock_release_holdtime.part.8+0xf/0x16e
[<ffffffff81079b05>] do_group_exit+0x47/0xb5
[<ffffffff81086c16>] get_signal_to_deliver+0x241/0x62f
[<ffffffff810020a7>] do_signal+0x43/0x59d
[<ffffffff810f2af7>] ? __audit_syscall_exit+0x21a/0x2a8
[<ffffffff810b4bfb>] ? lock_release_holdtime.part.8+0xf/0x16e
[<ffffffff81002655>] do_notify_resume+0x54/0x6c
[<ffffffff817abaf8>] int_signal+0x12/0x17
Reported-by: Sami Farin <sami.farin@gmail.com>
Cc: <stable@vger.kernel.org> # 3.12.x
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty flip buffers use GFP_ATOMIC allocations for received data
which is to be processed by the line discipline. For each byte
received, an extra byte is used to indicate the error status of
that byte.
Instead, if the received data is error-free, encode the entire
buffer without status bytes.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d7a68be4f2,
'tty: Only perform flip buffer flush from tty_buffer_flush()',
removed buffer flushing from flush_to_ldisc().
Fix function header comment which describes the former behavior.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up
the PM callbacks.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Don't use DEFINE_PCI_DEVICE_TABLE macro, because this macro
is not preferred.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Making DMA RX polling optional when DMA is on was just
over-cautious: there is one single system in the kernel tree
using this facility, Ux500 and after some testing I turned
this on also for Ux500, which means it should simply be on
by default if DMA is enabled.
Cc: Jongsung Kim <neidhard.kim@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up
the PM callbacks.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ttyA has ld associated to n_gsm, when ttyA is closing, it triggers
to release gsmttyB's ld data dlci[B], then race would happen if gsmttyB
is opening in parallel.
(Note: This patch set differs from previous set in that it uses mutex
instead of spin lock to avoid race, so that it avoids sleeping in automic
context)
Here are race cases we found recently in test:
CASE #1
====================================================================
releasing dlci[B] race with gsmtty_install(gsmttyB), then panic
in gsmtty_open(gsmttyB), as below:
tty_release(ttyA) tty_open(gsmttyB)
| |
----- gsmtty_install(gsmttyB)
| |
----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B]
tty_ldisc_release(ttyA) -----
| |
gsm_dlci_release(dlci[B]) -----
| |
gsm_dlci_free(dlci[B]) -----
| |
----- gsmtty_open(gsmttyB)
gsmtty_open()
{
struct gsm_dlci *dlci = tty->driver_data; => here it uses dlci[B]
...
}
In gsmtty_open(gsmttyA), it uses dlci[B] which was release, so hit a panic.
=====================================================================
CASE #2
=====================================================================
releasing dlci[0] race with gsmtty_install(gsmttyB), then panic
in gsmtty_open(), as below:
tty_release(ttyA) tty_open(gsmttyB)
| |
----- gsmtty_install(gsmttyB)
| |
----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B]
| |
----- gsmtty_open(gsmttyB) fail
| |
----- tty_release(gsmttyB)
| |
----- gsmtty_close(gsmttyB)
| |
----- gsmtty_detach_dlci(dlci[B])
| |
----- dlci_put(dlci[B])
| |
tty_ldisc_release(ttyA) -----
| |
gsm_dlci_release(dlci[0]) -----
| |
gsm_dlci_free(dlci[0]) -----
| |
----- dlci_put(dlci[0])
In gsmtty_detach_dlci(dlci[B]), it tries to use dlci[0] which was released,
then hit panic.
=====================================================================
IMHO, n_gsm tty operations would refer released ldisc, as long as
gsm_dlci_release() has chance to release ldisc data when some gsmtty operations
are ongoing..
This patch is try to avoid it by:
1) in n_gsm driver, use a global gsm mutex lock to avoid gsm_dlci_release() run in
parallel with gsmtty_install();
2) Increase dlci's ref count in gsmtty_install() instead of in gsmtty_open(), the
purpose is to prevent gsm_dlci_release() releasing dlci after gsmtty_install()
allocats dlci but before gsmtty_open increases dlci's ref count;
3) Decrease dlci's ref count in gsmtty_remove(), a tty framework API, this is the
opposite process of step 2).
Signed-off-by: Chao Bi <chao.bi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no in-tree user of tty_prepare_flip_string_flags(); remove.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trim up the memory_used field name to mem_used.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hendrik Brueckner
Marek Roszko
Stephen Warren
Mark Deneen
Qipan Li
Alexander Shiyan
Arnd Bergmann
Paul Gortmaker
Greg Kroah-Hartman
Qixue Xiao
Yegor Yefremov
Jonathan Woithe
Chuansheng Liu
Soren Brinkmann
Peter Hurley
Mika Westerberg
Rashika Kheria
Guennadi Liakhovetski
Jon Medhurst
James Hogan
Fabio Estevam
Ulf Hansson
Jingoo Han
Huang Shijie
Linus Walleij
Chao Bi