From 2586bba3a5157227254cd0a65f196aa36a7291f1 Mon Sep 17 00:00:00 2001 From: Robin Gong Date: Tue, 11 May 2021 18:18:01 +0800 Subject: [PATCH] MLK-25482: watchdog: imx2_wdt: clear WDOG_HW_RUNNING before suspend For watchdog_ping_work is not freezable so that it maybe scheduled before imx2_wdt_resume where watchdog clock is on, hence, kernel will hang in imx2_wdt_ping with clock disabled, 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 Reviewed-by: Jacky Bai --- 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 b84f80f7d342..d3751e9d2356 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; -- 2.17.1