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author | Damien Riegel <damien.riegel@savoirfairelinux.com> | 2015-11-20 21:54:51 (GMT) |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2015-12-13 14:55:51 (GMT) |
commit | e131319669e0ef5e6fcd75174daeffa40492135c (patch) | |
tree | 3ea2434a3d6661fd62b51efd1cfad7d0ac1c5052 /drivers | |
parent | 0ebad1e5e5bae3e59125675d37a70d946f283fef (diff) | |
download | linux-e131319669e0ef5e6fcd75174daeffa40492135c.tar.xz |
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 'drivers')
-rw-r--r-- | drivers/watchdog/watchdog_core.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index 88a34ef..0bb32a4 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) |