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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 10 Jun 2020 14:04:42 +0200
Message-ID: <CAMuHMdW541J7y8fotLD4jYpzpqLGC=nfc52NV55jMVndXbR-AQ@mail.gmail.com>
Subject: Re: [PATCH] gpio: rcar: handle pm_runtime_get_sync failure case
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     Navid Emamdoost <navid.emamdoost@gmail.com>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Navid Emamdoost <emamd001@umn.edu>,
        Qiushi Wu <wu000273@umn.edu>, Kangjie Lu <kjlu@umn.edu>,
        Stephen McCamant <smccaman@umn.edu>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Mark Brown <broonie@kernel.org>,
        Linux PM list <linux-pm@vger.kernel.org>
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Hi Linus,

On Wed, Jun 10, 2020 at 10:52 AM Linus Walleij <linus.walleij@linaro.org> wrote:
> On Fri, Jun 5, 2020 at 4:49 AM Navid Emamdoost
> <navid.emamdoost@gmail.com> wrote:
> > Calling pm_runtime_get_sync increments the counter even in case of
> > failure, causing incorrect ref count. Call pm_runtime_put if
> > pm_runtime_get_sync fails.
> >
> > Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> > ---
> >  drivers/gpio/gpio-rcar.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
> > index 7284473c9fe3..eac1582c70da 100644
> > --- a/drivers/gpio/gpio-rcar.c
> > +++ b/drivers/gpio/gpio-rcar.c
> > @@ -250,8 +250,10 @@ static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
> >         int error;
> >
> >         error = pm_runtime_get_sync(p->dev);
> > -       if (error < 0)
> > +       if (error < 0) {
> > +               pm_runtime_put(p->dev);
> >                 return error;
> > +       }
>
> I need Geert's review on this, he's usually on top of the Renesas stuff.

TBH, I don't know anymore _which_ is the right call to make...

"Re: [PATCH] spi: spi-ti-qspi: call pm_runtime_put on pm_runtime_get failure"
https://lore.kernel.org/linux-spi/20200602095411.GB5684@sirena.org.uk/

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds