[PATCH v2 5/8] watchdog: core: Restore WDOG_HW_RUNNING if stopping watchdog fails

[Guenter Roeck <linux@roeck-us.net>]

In watchdog_stop(), WDOG_HW_RUNNING is cleared before calling
wdd->ops->stop(). If wdd->ops->stop() returns an error, WDOG_ACTIVE
remains set, but WDOG_HW_RUNNING is left cleared. As a result,
subsequent calls to watchdog_ping() become no-ops, and
watchdog_release() sees watchdog_hw_running() as false and drops the
module and device references while the ping worker (guided by
WDOG_ACTIVE) continues to run.

Restore WDOG_HW_RUNNING if wdd->ops->stop() fails.

Fixes: 3c10bbde10fe ("watchdog: core: Clear WDOG_HW_RUNNING before calling the stop function")
Assisted-by: LLM
Cc: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Moved setting WDOG_HW_RUNNING to error handling after stop() call

 drivers/watchdog/watchdog_dev.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index af756ee228b2..47b0735ed6ac 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -312,6 +312,7 @@ static int watchdog_stop(struct watchdog_device *wdd)
 		clear_bit(WDOG_HW_RUNNING, &wdd->status);
 		err = wdd->ops->stop(wdd);
 		if (err < 0) {
+			set_bit(WDOG_HW_RUNNING, &wdd->status);
 			pr_err("watchdog%d: Failed to stop watchdog: %pe\n",
 			       wdd->id, ERR_PTR(err));
 		}
-- 
2.45.2