Commit e0b101ab authored by Robin Gong's avatar Robin Gong Committed by Wim Van Sebroeck
Browse files

watchdog: imx2_wdt: avoid to ping before resume back 



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. Add clk_is_on
to prevent the above case by ignoring ping until watchdog driver resume
back indeed.

Signed-off-by: default avatarRobin Gong <yibin.gong@nxp.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1621012875-22667-1-git-send-email-yibin.gong@nxp.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent 76215889

drivers/watchdog/imx2_wdt.c

+10 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ struct imx2_wdt_device { 
	struct regmap *regmap;

	struct watchdog_device wdog;

	bool ext_reset;

	bool clk_is_on;

};



static bool nowayout = WATCHDOG_NOWAYOUT;
@@ -160,6 +161,9 @@ static int imx2_wdt_ping(struct watchdog_device *wdog) 
{

	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);



	if (!wdev->clk_is_on)

		return 0;



	regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);

	regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);

	return 0;
@@ -301,6 +305,8 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) 
	if (ret)

		return ret;



	wdev->clk_is_on = true;



	regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);

	wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
@@ -361,6 +367,8 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev) 


	clk_disable_unprepare(wdev->clk);



	wdev->clk_is_on = false;



	return 0;

}
@@ -375,6 +383,8 @@ static int __maybe_unused imx2_wdt_resume(struct device *dev) 
	if (ret)

		return ret;



	wdev->clk_is_on = true;



	if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {

		/*

		 * If the watchdog is still active and resumes