Instrumented testing shows a tty can be hungup multiple times [1].
Although concurrent hangups are properly serialized, multiple
hangups for the same tty should be prevented.
If tty has already been HUPPED, abort hangup. Note it is not
necessary to cleanup file *redirect on subsequent hangups,
as only TIOCCONS can set that value and ioctls are disabled
after hangup.
[1]
Test performed by simulating a concurrent async hangup via
tty_hangup() with a sync hangup via tty_vhangup(), while
__tty_hangup() was instrumented with:
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 26bb78c..fe8b061 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -629,6 +629,8 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
tty_lock(tty);
+ WARN_ON(test_bit(TTY_HUPPED, &tty->flags));
+
/* some functions below drop BTM, so we need this bit */
set_bit(TTY_HUPPING, &tty->flags);
Test result:
WARNING: at /home/peter/src/kernels/mainline/drivers/tty/tty_io.c:632 __tty_hangup+0x459/0x460()
Modules linked in: ip6table_filter ip6_tables ebtable_nat <...snip...>
CPU: 6 PID: 1197 Comm: kworker/6:2 Not tainted 3.10.0-0+rfcomm-xeon #0+rfcomm
Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012
Workqueue: events do_tty_hangup
0000000000000009 ffff8802b16d7d18 ffffffff816b553e ffff8802b16d7d58
ffffffff810407e0 ffff880254f95c00 ffff880254f95c00 ffff8802bfd92b00
ffff8802bfd96b00 ffff880254f95e40 0000000000000180 ffff8802b16d7d68
Call Trace:
[<ffffffff816b553e>] dump_stack+0x19/0x1b
[<ffffffff810407e0>] warn_slowpath_common+0x70/0xa0
[<ffffffff8104082a>] warn_slowpath_null+0x1a/0x20
[<ffffffff813fb279>] __tty_hangup+0x459/0x460
[<ffffffff8107409c>] ? finish_task_switch+0xbc/0xe0
[<ffffffff813fb297>] do_tty_hangup+0x17/0x20
[<ffffffff8105fd6f>] process_one_work+0x16f/0x450
[<ffffffff8106007c>] process_scheduled_works+0x2c/0x40
[<ffffffff8106060a>] worker_thread+0x26a/0x380
[<ffffffff810603a0>] ? rescuer_thread+0x310/0x310
[<ffffffff810698a0>] kthread+0xc0/0xd0
[<ffffffff816b0000>] ? destroy_compound_page+0x65/0x92
[<ffffffff810697e0>] ? kthread_create_on_node+0x130/0x130
[<ffffffff816c495c>] ret_from_fork+0x7c/0xb0
[<ffffffff810697e0>] ? kthread_create_on_node+0x130/0x130
---[ end trace 98d9f01536cf411e ]---
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces switch in probe function to constant structure
for each supported IC. This makes code a bit smaller and cleaner and
helps adding DT support to the driver in the future.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes "frequency" parameter from SCCNXP platform_data
and uses CLK API for getting clock. If CLK ommited, default IC
frequency will be used instead.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The patch disables the regulator in case of errors, if we have it.
In addition, the patch adds support for deferred regulator probe and
makes error path are a bit clean.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pdev->id is not a valid choice for device-tree probed devices. So use
the (properly determined) line from efm32_uart_probe consistenly
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Storing one struct per known board would be overkill. Pre-cast the
driver_data pointer to an unsigned long to avoid the pointer to int
compiler warning:
drivers/tty/serial/pch_uart.c:431:10: warning: cast from pointer to
integer of different size [-Wpointer-to-int-cast]
Unify the signed-ness of the baud and uartclk types throughout the
driver.
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because the UART lack of receive timeout register, so we use a timer to trigger
data receive.
The DBGU is regarded as UART.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Distinguish usart and uart by read ip name register,
The usart read name is "USAR",
The uart and dbgu read name is "DBGU".
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will switch to pio mode when request of dma or pdc fail.
But soon or later, when the request is success, the transfer mode can switch to them at
next open serial port action.
So in startup stage, we should get original transfer mode.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Request a cyclic dma channel for rx dma use. Use cyclic transfer is to prevent
receive data overrun.
We allocate a cycle dma cookie after request channel,
after that, enable uart timeout interrupt in startup stage, when data successful
received, the timeout callback will check the residual bytes and insert
receiving datas into the framework during the transfer interval.
When current descriptor finished, the dma callback will also check the residual
bytes and filp the receiving data.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Request a slave dma channel for tx dma use. Tx dma will setup a single transfer,
when transfer complete, it will call atmel_complete_tx_dma to do finish stuff.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
use function pointer can avoid define atmel_use_pdc_tx/rx everywhere.
(*prepare_rx/tx)() is in setup transfer stage.
(*schedule_rx/tx)() is in tasklet schedule stage.
(*release_rx/tx)() is used when shutdown the transfer.
Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dmi_table is best accessed from the probe function, which is not
an __init function. Drop the __initdata annotation from the dmi_table
to avoid the section mismatch compiler warnings:
WARNING: drivers/tty/serial/pch_uart.o(.text+0x4871): Section mismatch
in reference from the function pch_uart_init_port() to the variable
.init.data:pch_uart_dmi_table
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes wrong dev_pm_ops which caused by commit:
serial: max310x: Driver rework.
CC drivers/tty/serial/max310x.o
LD drivers/video/fb.o
CC drivers/w1/slaves/w1_ds2433.o
CC drivers/w1/slaves/w1_ds2760.o
CC drivers/xen/balloon.o
CC drivers/video/backlight/adp8870_bl.o
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.suspend') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.resume') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.freeze') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.thaw') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.poweroff') [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/max310x.c:1292:8: warning: (near initialization for 'max310x_pm_ops.restore') [enabled by default]
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull pin control fixes from Linus Walleij:
- Driver fixes for AM33xx, SIRF and PFC pin controllers
- Fix a compile warning from the pinctrl single-register driver
- Fix a little nasty memory leak
* tag 'pinctrl-for-v3.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: fix a memleak when freeing maps
pinctrl: pinctrl-single: fix compile warning when no CONFIG_PM
pinctrl: sh-pfc: fix SDHI0 VccQ regulator on sh73a0 with DT
arm/dts: sirf: fix the pingroup name mismatch between drivers and dts
pinctrl: sirf: add usp0_uart_nostreamctrl pin group for usp-uart without flowctrl
pinctrl: sirf: fix the pin number and mux bit for usp0
pinctrl: am33xx dt binding: correct include path
Vineet Gupta
Peter Hurley
Alexander Shiyan
Uwe Kleine-König
Jingoo Han
Darren Hart
Elen Song
Alexandru Juncu
Greg Kroah-Hartman
Linus Torvalds