On 2023/4/25 22:06, Guenter Roeck wrote: > On 4/25/23 03:04, Xingyu Wu wrote: >> When the starfive watchdog driver uses 'pm_runtime_put_sync()' as probe >> return value at last and 'early_enable' is disabled, it could return the >> error '-ENOSYS' if the CONFIG_PM is disabled, but the driver should works >> normally. >> >> Add a check to make sure the PM is enabled and then use >> 'pm_runtime_put_sync()' as return value when 'early_enable' is disabled. >> >> Fixes: db728ea9c7be ("drivers: watchdog: Add StarFive Watchdog driver") >> Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx> >> --- >> >> Hi, Guenter and Wim, >> >> This patch fixes the issue of StarFive watchdog driver and rebases on >> the master branch of linux-next. >> >> Thanks. >> --- >> drivers/watchdog/starfive-wdt.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/watchdog/starfive-wdt.c b/drivers/watchdog/starfive-wdt.c >> index 1995cceca51e..51e487e09960 100644 >> --- a/drivers/watchdog/starfive-wdt.c >> +++ b/drivers/watchdog/starfive-wdt.c >> @@ -492,7 +492,8 @@ static int starfive_wdt_probe(struct platform_device *pdev) >> goto err_exit; >> if (!early_enable) >> - return pm_runtime_put_sync(&pdev->dev); >> + if (pm_runtime_enabled(&pdev->dev)) >> + return pm_runtime_put_sync(&pdev->dev); >> > > Why not just > > if (!early_enable) > pm_runtime_put_sync(&pdev->dev) > > like almost every other caller of pm_runtime_put_sync() ? > The function of pm_runtime_put_sync() is that: static inline int pm_runtime_put_sync(struct device *dev) { return __pm_runtime_idle(dev, RPM_GET_PUT); } and when do not enable CONFIG_PM, the __pm_runtime_idle() is that: static inline int __pm_runtime_idle(struct device *dev, int rpmflags) { return -ENOSYS; } If I do not open PM, it will return error saying probe failed but it works fine without PM. I had tested that and probe really was failed. So I should add this check before using pm_runtime_put_sync(). Best regards, Xingyu Wu