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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Jan Kiszka <jan.kiszka@siemens.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        Sasha Levin <sashal@kernel.org>, linux-watchdog@vger.kernel.org
Subject: [PATCH AUTOSEL 5.14 20/32] watchdog: Start watchdog in watchdog_set_last_hw_keepalive only if appropriate
Date:   Sat, 11 Sep 2021 09:11:37 -0400
Message-Id: <20210911131149.284397-20-sashal@kernel.org>
In-Reply-To: <20210911131149.284397-1-sashal@kernel.org>
References: <20210911131149.284397-1-sashal@kernel.org>
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From: Jan Kiszka <jan.kiszka@siemens.com>

[ 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@siemens.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/93d56386-6e37-060b-55ce-84de8cde535f@web.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/watchdog/watchdog_dev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 3bab32485273..6c73160386b9 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -1172,7 +1172,10 @@ 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);
 
-- 
2.30.2