linux-kernel - Re: [PATCH 6/6] nvmem: increase the reference count of a gpio passed over config

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Message-ID: <CAMuHMdWAxhUWPt06vcaHwD34=k=ihzVAxSTtFnO4r2bY7nAmjA@mail.gmail.com>
Date:   Mon, 17 Feb 2020 22:13:17 +0100
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Khouloud Touil <ktouil@...libre.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH 6/6] nvmem: increase the reference count of a gpio passed
 over config

Hi Bartosz,

On Mon, Feb 17, 2020 at 8:56 PM Bartosz Golaszewski <brgl@...ev.pl> wrote:
> From: Bartosz Golaszewski <bgolaszewski@...libre.com>
>
> We can obtain the write-protect GPIO in nvmem_register() by requesting
> it ourselves or by storing the gpio_desc passed in nvmem_config. In the
> latter case we need to increase the reference count so that it gets
> freed correctly.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>

Thanks for your patch!

> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -349,11 +349,13 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
>                 return ERR_PTR(rval);
>         }
>
> -       if (config->wp_gpio)
> +       if (config->wp_gpio) {
>                 nvmem->wp_gpio = config->wp_gpio;
> -       else
> +               gpiod_ref(config->wp_gpio);

If gpiod_ref() would return the passed GPIO, or an error code, you could write

        nvmem->wp_gpio = gpiod_ref(config->wp_gpio);

> +       } else {
>                 nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
>                                                     GPIOD_OUT_HIGH);
> +       }
>         if (IS_ERR(nvmem->wp_gpio))
>                 goto err_ida_remove;
>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-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