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| author | Damien Riegel <damien.riegel@savoirfairelinux.com> | 2015-11-20 22:54:51 +0100 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2015-12-13 15:55:51 +0100 |
| commit | e131319669e0ef5e6fcd75174daeffa40492135c (patch) | |
| tree | 3ea2434a3d6661fd62b51efd1cfad7d0ac1c5052 /Documentation/watchdog/watchdog-kernel-api.txt | |
| parent | watchdog: sunxi_wdt: use core restart handler (diff) | |
| download | linux-e131319669e0ef5e6fcd75174daeffa40492135c.tar.xz linux-e131319669e0ef5e6fcd75174daeffa40492135c.zip | |
watchdog: core: add reboot notifier support
Many watchdog drivers register a reboot notifier in order to stop the
watchdog on system reboot. Thus we can factorize this code in the
watchdog core.
For that purpose, a new notifier block is added in watchdog_device for
internal use only, as well as a new watchdog_stop_on_reboot helper
function.
If this helper is called, watchdog core registers the related notifier
block and will stop the watchdog when SYS_HALT or SYS_DOWN is received.
Since this operation can be critical on some platforms, abort the device
registration if the reboot notifier registration fails.
Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'Documentation/watchdog/watchdog-kernel-api.txt')
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index dbc6a65f0bd1..0a37da76acef 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -53,6 +53,7 @@ struct watchdog_device { unsigned int timeout; unsigned int min_timeout; unsigned int max_timeout; + struct notifier_block reboot_nb; struct notifier_block restart_nb; void *driver_data; struct mutex lock; @@ -76,6 +77,9 @@ It contains following fields: * timeout: the watchdog timer's timeout value (in seconds). * min_timeout: the watchdog timer's minimum timeout value (in seconds). * max_timeout: the watchdog timer's maximum timeout value (in seconds). +* reboot_nb: notifier block that is registered for reboot notifications, for + internal use only. If the driver calls watchdog_stop_on_reboot, watchdog core + will stop the watchdog on such notifications. * restart_nb: notifier block that is registered for machine restart, for internal use only. If a watchdog is capable of restarting the machine, it should define ops->restart. Priority can be changed through @@ -240,6 +244,10 @@ to set the default timeout value as timeout value in the watchdog_device and then use this function to set the user "preferred" timeout value. This routine returns zero on success and a negative errno code for failure. +To disable the watchdog on reboot, the user must call the following helper: + +static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd); + To change the priority of the restart handler the following helper should be used: |