This is a note to let you know that I've just added the patch titled watchdog: mei_wdt: request stop on unregister to the 4.19-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-mei_wdt-request-stop-on-unregister.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 740c0a57b8f1e36301218bf549f3c9cc833a60be Mon Sep 17 00:00:00 2001 From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> Date: Sun, 24 Jan 2021 13:49:38 +0200 Subject: watchdog: mei_wdt: request stop on unregister From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> commit 740c0a57b8f1e36301218bf549f3c9cc833a60be upstream. The MEI bus has a special behavior on suspend it destroys all the attached devices, this is due to the fact that also firmware context is not persistent across power flows. If watchdog on MEI bus is ticking before suspending the firmware times out and reports that the OS is missing watchdog tick. Send the stop command to the firmware on watchdog unregistered to eliminate the false event on suspend. This does not make the things worse from the user-space perspective as a user-space should re-open watchdog device after suspending before this patch. Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx> Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210124114938.373885-1-tomas.winkler@xxxxxxxxx Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/watchdog/mei_wdt.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/watchdog/mei_wdt.c +++ b/drivers/watchdog/mei_wdt.c @@ -382,6 +382,7 @@ static int mei_wdt_register(struct mei_w watchdog_set_drvdata(&wdt->wdd, wdt); watchdog_stop_on_reboot(&wdt->wdd); + watchdog_stop_on_unregister(&wdt->wdd); ret = watchdog_register_device(&wdt->wdd); if (ret) { Patches currently in stable-queue which might be from alexander.usyskin@xxxxxxxxx are queue-4.19/watchdog-mei_wdt-request-stop-on-unregister.patch