From: Guenter Roeck <linux@roeck-us.net>
To: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH 5/8] watchdog: core: Restore WDOG_HW_RUNNING if stopping watchdog fails
Date: Tue, 29 Sep 2026 06:46:32 -0700 [thread overview]
Message-ID: <20260929134635.2567137-6-linux@roeck-us.net> (raw)
In-Reply-To: <20260929134635.2567137-1-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
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/watchdog/watchdog_dev.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index af756ee228b2..edf2cccd1c0e 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -324,6 +324,8 @@ static int watchdog_stop(struct watchdog_device *wdd)
clear_bit(WDOG_ACTIVE, &wdd->status);
watchdog_update_worker(wdd);
watchdog_hrtimer_pretimeout_stop(wdd);
+ } else {
+ set_bit(WDOG_HW_RUNNING, &wdd->status);
}
return err;
--
2.45.2
next prev parent reply other threads:[~2026-09-29 13:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-29 13:46 [PATCH 0/8] watchdog: core: Fix locking, lifetime, suspend, and state management bugs Guenter Roeck
2026-09-29 13:46 ` [PATCH 1/8] watchdog: core: Clear wd_data pointer on errors Guenter Roeck
2026-09-29 13:46 ` [PATCH 2/8] watchdog: core: Add missing locks Guenter Roeck
2026-09-29 13:46 ` [PATCH 3/8] watchdog: core: Prevent ping worker from re-arming timer on suspend Guenter Roeck
2026-09-29 13:46 ` [PATCH 4/8] watchdog: core: Stop pretimeout hrtimer " Guenter Roeck
2026-09-29 13:46 ` Guenter Roeck [this message]
2026-09-29 13:46 ` [PATCH 6/8] watchdog: core: Cancel timer if cdev_device_add() fails Guenter Roeck
2026-09-29 13:46 ` [PATCH 7/8] watchdog: core: Fix unbalanced module_put() in watchdog_open() Guenter Roeck
2026-09-29 13:46 ` [PATCH 8/8] watchdog: core: Update last_keepalive in watchdog_start() Guenter Roeck
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