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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 17 Jun 2020 09:26:47 +0200
Message-ID: <CAMuHMdXHT9y09L19j2K=oQ1W+7x=SE7MEyjj6r1i=DPcokvWzg@mail.gmail.com>
Subject: Re: [PATCH] gpio: rcar: handle pm_runtime_get_sync failure case
To:     Navid Emamdoost <navid.emamdoost@gmail.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Linux Kernel Mailing List <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>
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Hi Navid,

On Fri, Jun 5, 2020 at 4:50 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>

Thanks for your patch!

> --- 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);

As per [1], I would like to see a call to pm_runtime_put_noidle() instead.

[1] http://lore.kernel.org/r/CAJZ5v0i87NGcy9+kxubScdPDyByr8ypQWcGgBFn+V-wDd69BHQ@mail.gmail.com

>                 return error;
> +       }
>
>         error = pinctrl_gpio_request(chip->base + offset);
>         if (error)

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