Re: [PATCH v1] gpiolib: Don't WARN on gpiod_put() for optional GPIO

[Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>]

wt., 2 kwi 2019 o 12:49 Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> napisał(a):
>
> On Tue, Mar 26, 2019 at 09:44:20PM +0200, Andy Shevchenko wrote:
> > On Tue, Mar 26, 2019 at 06:48:25PM +0100, Bartosz Golaszewski wrote:
> > > wt., 26 mar 2019 o 16:21 Andy Shevchenko
> > > <andriy.shevchenko@xxxxxxxxxxxxxxx> napisał(a):
> > > >
> > > > In case of debug and optional GPIO requested, the gpiod_put() is not aware of
> > > > and will WARN, which is not the case.
> > > >
> > > > Make gpiod_put() NULL-aware to keep silent for optional GPIOs.
> > > >
> > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > > > ---
> > > >  drivers/gpio/gpiolib.c | 3 ++-
> > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> > > > index 144af0733581..36445e24ee89 100644
> > > > --- a/drivers/gpio/gpiolib.c
> > > > +++ b/drivers/gpio/gpiolib.c
> > > > @@ -4616,7 +4616,8 @@ EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
> > > >   */
> > > >  void gpiod_put(struct gpio_desc *desc)
> > > >  {
> > > > -       gpiod_free(desc);
> > > > +       if (desc)
> > > > +               gpiod_free(desc);
> > > >  }
> > > >  EXPORT_SYMBOL_GPL(gpiod_put);
> > > >
> > > > --
> > > > 2.20.1
> > > >
> > >
> > > In that case I don't think we need to keep checking desc for NULL in
> > > gpiod_free().
> >
> > I didn't remove the check there because it's called more than just from
> > gpiod_put(). I didn't check all code paths myself. So, if it seems good for you
> > to remove the check I can do it in next version.
>
> Any additional comments on this? I have looked briefly at this and found that
> gpiod_free() is used to support legacy gpio_free() which is used in a plenty of
> drivers. There are more than dozen are using non static number for these calls.
>
> I think the patch as is is the best approach we can do right now.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Now applied.

Bart