| Message ID | 1621012875-22667-1-git-send-email-yibin.gong@nxp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] watchdog: imx2_wdt: avoid to ping before resume back | expand |
On 5/14/21 10:21 AM, Robin Gong wrote: > 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: Robin Gong <yibin.gong@nxp.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/imx2_wdt.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c > index b84f80f..cc86018 100644 > --- a/drivers/watchdog/imx2_wdt.c > +++ b/drivers/watchdog/imx2_wdt.c > @@ -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 >
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index b84f80f..cc86018 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -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
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: Robin Gong <yibin.gong@nxp.com> --- drivers/watchdog/imx2_wdt.c | 10 ++++++++++ 1 file changed, 10 insertions(+)