From: Robin Gong <yibin.gong@nxp.com>
To: wim@linux-watchdog.org, linux@roeck-us.net, shawnguo@kernel.org,
s.hauer@pengutronix.de, festevam@gmail.com
Cc: linux-imx@nxp.com, kernel@pengutronix.de,
linux-watchdog@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v1] watchdog: imx2_wdt: clear WDOG_HW_RUNNING before suspend
Date: Tue, 11 May 2021 19:20:32 +0800 [thread overview]
Message-ID: <1620732032-7675-1-git-send-email-yibin.gong@nxp.com> (raw)
Since watchdog_ping_work is not freezable so that it maybe scheduled before
imx2_wdt_resume where watchdog clock enabled, hence, kernel will hang in
imx2_wdt_ping without clock, and then watchdog reset happen. Prevent the
above case by clearing WDOG_HW_RUNNING before suspend, and restore it with
ping in imx2_wdt_resume.
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
---
drivers/watchdog/imx2_wdt.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index b84f80f..d3751e9 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -357,6 +357,13 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev)
*/
__imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
imx2_wdt_ping(wdog);
+
+ /*
+ * clear WDOG_HW_RUNNING to prevent watchdog_ping_work running
+ * before imx2_wdt_resume where clock enabled, otherwise kernel
+ * will hang and watchdog reset happen then.
+ */
+ clear_bit(WDOG_HW_RUNNING, &wdog->status);
}
clk_disable_unprepare(wdev->clk);
@@ -386,6 +393,7 @@ static int __maybe_unused imx2_wdt_resume(struct device *dev)
if (imx2_wdt_is_running(wdev)) {
imx2_wdt_set_timeout(wdog, wdog->timeout);
imx2_wdt_ping(wdog);
+ set_bit(WDOG_HW_RUNNING, &wdog->status);
}
return 0;
--
2.7.4
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next reply other threads:[~2021-05-11 10:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 11:20 Robin Gong [this message]
2021-05-11 3:59 ` [PATCH v1] watchdog: imx2_wdt: clear WDOG_HW_RUNNING before suspend Guenter Roeck
2021-05-12 11:34 ` Robin Gong
2021-05-12 14:14 ` Guenter Roeck
2021-05-13 3:49 ` Robin Gong
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