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authorGrzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>2021-06-18 22:50:32 +0300
committerWim Van Sebroeck <wim@linux-watchdog.org>2021-08-22 11:28:08 +0300
commit60bcd91aafd22ef62cef9ae2037fa2e1d4da2fb3 (patch)
tree918b076b7d7ab529aa5f26f101864a6505ad4802 /drivers/watchdog/watchdog_core.c
parentc7b178dae139f8857edc50888cfbf251cd974a38 (diff)
downloadlinux-60bcd91aafd22ef62cef9ae2037fa2e1d4da2fb3.tar.xz
watchdog: introduce watchdog_dev_suspend/resume
The watchdog drivers often disable wdog clock during suspend and then enable it again during resume. Nevertheless the ping worker is still running and can issue low-level ping while the wdog clock is disabled causing the system hang. To prevent such condition register pm notifier in the watchdog core which will call watchdog_dev_suspend/resume and actually cancel ping worker during suspend and restore it back, if needed, during resume. Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20210618195033.3209598-2-grzegorz.jaszczyk@linaro.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
-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 5df0a22e2cb4..3fe8a7edc252 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -34,6 +34,7 @@
#include <linux/idr.h> /* For ida_* macros */
#include <linux/err.h> /* For IS_ERR macros */
#include <linux/of.h> /* For of_get_timeout_sec */
+#include <linux/suspend.h>
#include "watchdog_core.h" /* For watchdog_dev_register/... */
@@ -185,6 +186,33 @@ static int watchdog_restart_notifier(struct notifier_block *nb,
return NOTIFY_DONE;
}
+static int watchdog_pm_notifier(struct notifier_block *nb, unsigned long mode,
+ void *data)
+{
+ struct watchdog_device *wdd;
+ int ret = 0;
+
+ wdd = container_of(nb, struct watchdog_device, pm_nb);
+
+ switch (mode) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_RESTORE_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ ret = watchdog_dev_suspend(wdd);
+ break;
+ case PM_POST_HIBERNATION:
+ case PM_POST_RESTORE:
+ case PM_POST_SUSPEND:
+ ret = watchdog_dev_resume(wdd);
+ break;
+ }
+
+ if (ret)
+ return NOTIFY_BAD;
+
+ return NOTIFY_DONE;
+}
+
/**
* watchdog_set_restart_priority - Change priority of restart handler
* @wdd: watchdog device
@@ -292,6 +320,15 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
wdd->id, ret);
}
+ if (test_bit(WDOG_NO_PING_ON_SUSPEND, &wdd->status)) {
+ wdd->pm_nb.notifier_call = watchdog_pm_notifier;
+
+ ret = register_pm_notifier(&wdd->pm_nb);
+ if (ret)
+ pr_warn("watchdog%d: Cannot register pm handler (%d)\n",
+ wdd->id, ret);
+ }
+
return 0;
}