Re: [PATCH v1] watchdog: starfive: Fix the probe return error if PM and early_enable are both disabled

[Guenter Roeck]

On 4/25/23 18:49, Xingyu Wu wrote:
> 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().

You did not answer my question.

Guenter