linux.git/Documentation/watchdog, branch v3.17

Documentation: fix two typos in watchdog-api.txt

2014-08-05T20:43:21+00:00

This patch changes 'go of' to 'go off' and 'pretimout' to
'pretimeout'.

Signed-off-by: Sangjung Woo 
Acked-by: Randy Dunlap 
Reviewed-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck

watchdog: it87_wdt: Work around non-working CIR interrupts

2014-03-31T11:33:55+00:00

On some hardware platforms, the it87_wdt watchdog resets the machine
despite the watchdog daemon running and writing to /dev/watchdog.

This is due to Consumer IR buffer underrun interrupts being used as
triggers to reset the timer.  On some buggy hardware implementations
such as the iEi AFL-12A-N270 single-board computer, this method does
not work.

However, resetting the timer by writing its original timeout value in
its configuration register over and over again suppresses the unwanted
reboots.

Add a module option (nocir), 0 by default in order not to break existing
setups.  Setting it to 1 enables the workaround.

Fixes bug #42801 .
Tested primarily on Linux 3.5.7, applies cleanly on Linux 3.13.5.

Signed-off-by: Marc van der Wal 
Reviewed-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck

watchdog: Add tegra watchdog

2014-03-31T11:30:29+00:00

Add a driver for the hardware watchdogs in NVIDIA Tegra SoCs (Tegra30 and
later).  This driver will configure one watchdog timer that will reset the
system in the case of a watchdog timeout.

This driver binds to the nvidia,tegra30-timer device node and gets its
register base from there.

Signed-off-by: Andrew Chew 
Reviewed-by: Guenter Roeck 
Tested-by: Stephen Warren 
Reviewed-by: Stephen Warren 
Signed-off-by: Wim Van Sebroeck

watchdog: delete mpcore_wdt driver

2013-07-11T19:47:58+00:00

Interrupt request doesn't use the right API: The TWD watchdog uses a per-cpu
interrupt (usually interrupt #30), and the GIC configuration should flag it as
such. With this setup, request_irq() should fail, and the right API is
request_percpu_irq(), together with enable_percpu_irq()/disable_percpu_irq().

Nothing ensures the userspace ioctl() will end-up kicking the watchdog on the
right CPU.

There are no users of this driver since a long time and it makes more sense to
get rid of it as nobody is looking to fix it.

In case somebody wakes up after this has been removed and needs it, please
revert this driver and pick these updates (These were never pushed to mainline):

http://comments.gmane.org/gmane.linux.ports.arm.kernel/245998

Signed-off-by: Viresh Kumar 
Acked-by: Guenter Roeck 
Signed-off-by: Wim Van Sebroeck

watchdog: core: dt: add support for the timeout-sec dt property

2013-03-01T11:48:36+00:00

Add support for watchdog drivers to initialize/set the timeout field
of the watchdog_device structure. The timeout field is initialised
either with the module timeout parameter value (if valid) or with the
timeout-sec dt property (if valid). If both are invalid the initial
value is unchanged.

Signed-off-by: Fabio Porcedda 
Acked-by: Nicolas Ferre 
Signed-off-by: Wim Van Sebroeck

watchdog: fix watchdog-test.c build warning

2012-08-29T15:12:58+00:00

Fix compiler warning by making the function static:

Documentation/watchdog/src/watchdog-test.c:34:6: warning: no previous prototype for 'term'

Signed-off-by: Randy Dunlap 
Signed-off-by: Wim Van Sebroeck

Watchdog: DA9052/53 PMIC watchdog support

2012-05-30T05:56:12+00:00

This driver adds support for the watchdog functionality provided by
the Dialog Semiconductor DA9052 PMIC chip.

Tested on samsung smdkv6410 and i.mx53 QS boards.

Signed-off-by: Anthony Olech 
Signed-off-by: Ashish Jangam 
Signed-off-by: Wim Van Sebroeck

watchdog: Add support for dynamically allocated watchdog_device structs

2012-05-30T05:55:31+00:00

If a driver's watchdog_device struct is part of a dynamically allocated
struct (which it often will be), merely locking the module is not enough,
even with a drivers module locked, the driver can be unbound from the device,
examples:
1) The root user can unbind it through sysfd
2) The i2c bus master driver being unloaded for an i2c watchdog

I will gladly admit that these are corner cases, but we still need to handle
them correctly.

The fix for this consists of 2 parts:
1) Add ref / unref operations, so that the driver can refcount the struct
   holding the watchdog_device struct and delay freeing it until any
   open filehandles referring to it are closed
2) Most driver operations will do IO on the device and the driver should not
   do any IO on the device after it has been unbound. Rather then letting each
   driver deal with this internally, it is better to ensure at the watchdog
   core level that no operations (other then unref) will get called after
   the driver has called watchdog_unregister_device(). This actually is the
   bulk of this patch.

Signed-off-by: Hans de Goede 
Signed-off-by: Wim Van Sebroeck

watchdog: Add Locking support

2012-05-30T05:55:23+00:00

This patch fixes some potential multithreading issues, despite only
allowing one process to open the /dev/watchdog device, we can still get
called multiple times at the same time, since a program could be using thread,
or could share the fd after a fork.

This causes 2 potential problems:
1) watchdog_start / open do an unlocked test_n_set / test_n_clear,
   if these 2 race, the watchdog could be stopped while the active
   bit indicates it is running or visa versa.

2) Most watchdog_dev drivers probably assume that only one
   watchdog-op will get called at a time, this is not necessary
   true atm.

Signed-off-by: Hans de Goede 
Signed-off-by: Wim Van Sebroeck

watchdog: create all the proper device files

2012-05-30T05:54:46+00:00

Create the watchdog class and it's associated devices.

Signed-off-by: Alan Cox 
Signed-off-by: Hans de Goede 
Signed-off-by: Wim Van Sebroeck