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authorDamien Riegel <damien.riegel@savoirfairelinux.com>2015-11-21 00:54:51 +0300
committerWim Van Sebroeck <wim@iguana.be>2015-12-13 17:55:51 +0300
commite131319669e0ef5e6fcd75174daeffa40492135c (patch)
tree3ea2434a3d6661fd62b51efd1cfad7d0ac1c5052 /drivers/watchdog
parent0ebad1e5e5bae3e59125675d37a70d946f283fef (diff)
downloadlinux-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/watchdog')
-rw-r--r--drivers/watchdog/watchdog_core.c37
1 files changed, 37 insertions, 0 deletions
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)