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@xxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
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
