diff options
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 8 | ||||
| -rw-r--r-- | drivers/watchdog/watchdog_core.c | 37 | ||||
| -rw-r--r-- | include/linux/watchdog.h | 9 |
3 files changed, 54 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: diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index 88a34efac400..0bb32a487f46 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -138,6 +138,25 @@ int watchdog_init_timeout(struct watchdog_device *wdd, } EXPORT_SYMBOL_GPL(watchdog_init_timeout); +static int watchdog_reboot_notifier(struct notifier_block *nb, + unsigned long code, void *data) +{ + struct watchdog_device *wdd = container_of(nb, struct watchdog_device, + reboot_nb); + + if (code == SYS_DOWN || code == SYS_HALT) { + if (watchdog_active(wdd)) { + int ret; + + ret = wdd->ops->stop(wdd); + if (ret) + return NOTIFY_BAD; + } + } + + return NOTIFY_DONE; +} + static int watchdog_restart_notifier(struct notifier_block *nb, unsigned long action, void *data) { @@ -238,6 +257,21 @@ static int __watchdog_register_device(struct watchdog_device *wdd) return ret; } + if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) { + wdd->reboot_nb.notifier_call = watchdog_reboot_notifier; + + ret = register_reboot_notifier(&wdd->reboot_nb); + if (ret) { + dev_err(wdd->dev, "Cannot register reboot notifier (%d)\n", + ret); + watchdog_dev_unregister(wdd); + device_destroy(watchdog_class, devno); + ida_simple_remove(&watchdog_ida, wdd->id); + wdd->dev = NULL; + return ret; + } + } + if (wdd->ops->restart) { wdd->restart_nb.notifier_call = watchdog_restart_notifier; @@ -286,6 +320,9 @@ static void __watchdog_unregister_device(struct watchdog_device *wdd) if (wdd->ops->restart) unregister_restart_handler(&wdd->restart_nb); + if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) + unregister_reboot_notifier(&wdd->reboot_nb); + devno = wdd->cdev.dev; ret = watchdog_dev_unregister(wdd); if (ret) diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h index 5b52c834f7aa..a88f955fde92 100644 --- a/include/linux/watchdog.h +++ b/include/linux/watchdog.h @@ -65,6 +65,7 @@ struct watchdog_ops { * @timeout: The watchdog devices timeout value (in seconds). * @min_timeout:The watchdog devices minimum timeout value (in seconds). * @max_timeout:The watchdog devices maximum timeout value (in seconds). + * @reboot_nb: The notifier block to stop watchdog on reboot. * @restart_nb: The notifier block to register a restart function. * @driver-data:Pointer to the drivers private data. * @lock: Lock for watchdog core internal use only. @@ -92,6 +93,7 @@ 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; @@ -102,6 +104,7 @@ struct watchdog_device { #define WDOG_ALLOW_RELEASE 2 /* Did we receive the magic char ? */ #define WDOG_NO_WAY_OUT 3 /* Is 'nowayout' feature set ? */ #define WDOG_UNREGISTERED 4 /* Has the device been unregistered */ +#define WDOG_STOP_ON_REBOOT 5 /* Should be stopped on reboot */ struct list_head deferred; }; @@ -121,6 +124,12 @@ static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool noway set_bit(WDOG_NO_WAY_OUT, &wdd->status); } +/* Use the following function to stop the watchdog on reboot */ +static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) +{ + set_bit(WDOG_STOP_ON_REBOOT, &wdd->status); +} + /* Use the following function to check if a timeout value is invalid */ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) { |