From 740c0a57b8f1e36301218bf549f3c9cc833a60be Mon Sep 17 00:00:00 2001
From: Alexander Usyskin <alexander.usyskin@intel.com>
Date: Sun, 24 Jan 2021 13:49:38 +0200
Subject: [PATCH] watchdog: mei_wdt: request stop on unregister
Git-commit: 740c0a57b8f1e36301218bf549f3c9cc833a60be
Patch-mainline: v5.12-rc1
References: git-fixes

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@vger.kernel.org>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210124114938.373885-1-tomas.winkler@intel.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

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

diff --git a/drivers/watchdog/mei_wdt.c b/drivers/watchdog/mei_wdt.c
index 5391bf3e6b11..c5967d8b4256 100644
--- a/drivers/watchdog/mei_wdt.c
+++ b/drivers/watchdog/mei_wdt.c
@@ -382,6 +382,7 @@ static int mei_wdt_register(struct mei_wdt *wdt)
 
 	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)
-- 
2.26.2