This is a note to let you know that I've just added the patch titled watchdog: Start watchdog in watchdog_set_last_hw_keepalive only if appropriate to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: watchdog-start-watchdog-in-watchdog_set_last_hw_keep.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 00db1cf5b7394878b806a54d00669a0ec2370e8c Author: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> Date: Sun Aug 1 09:56:25 2021 +0200 watchdog: Start watchdog in watchdog_set_last_hw_keepalive only if appropriate [ Upstream commit dbe80cf471f940db3063197b7adb1169f89be9ed ] We must not pet a running watchdog when handle_boot_enabled is off because this will kick off automatic triggering before userland is running, defeating the purpose of the handle_boot_enabled control. Furthermore, don't ping in case watchdog_set_last_hw_keepalive was called incorrectly when the hardware watchdog is actually not running. Fixed: cef9572e9af3 ("watchdog: add support for adjusting last known HW keepalive time") Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/93d56386-6e37-060b-55ce-84de8cde535f@xxxxxx Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 2946f3a63110..2ee017442dfc 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -1164,7 +1164,10 @@ int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd, wd_data->last_hw_keepalive = ktime_sub(now, ms_to_ktime(last_ping_ms)); - return __watchdog_ping(wdd); + if (watchdog_hw_running(wdd) && handle_boot_enabled) + return __watchdog_ping(wdd); + + return 0; } EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive);