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References: <20231002-gpiodoc-v1-1-a8ec8376bbf1@linaro.org>
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From:   Bartosz Golaszewski <brgl@bgdev.pl>
Date:   Wed, 4 Oct 2023 13:41:00 +0200
Message-ID: <CAMRc=Mc1ocs6aT9PdptBXSgKJOOva5wm00HwYse9oCY6UpE2Mw@mail.gmail.com>
Subject: Re: [PATCH] gpio: Further document optional GPIOLIB
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     Andy Shevchenko <andy@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>, linux-gpio@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
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On Mon, Oct 2, 2023 at 10:12=E2=80=AFAM Linus Walleij <linus.walleij@linaro=
.org> wrote:
>
> Optional GPIOLIB as in not depended on or selected by a driver
> should NOT use any *_optional() calls, this becomes paradoxical.
>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  Documentation/driver-api/gpio/consumer.rst | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/d=
river-api/gpio/consumer.rst
> index de6fc79ad6f0..3e588b9d678c 100644
> --- a/Documentation/driver-api/gpio/consumer.rst
> +++ b/Documentation/driver-api/gpio/consumer.rst
> @@ -29,6 +29,10 @@ warnings. These stubs are used for two use cases:
>    will use it under other compile-time configurations. In this case the
>    consumer must make sure not to call into these functions, or the user =
will
>    be met with console warnings that may be perceived as intimidating.
> +  Combining truly optional GPIOLIB usage with calls to
> +  ``[devm_]gpiod_get_optional()`` is a *bad idea*, and will result in we=
ird
> +  error messages. Use the ordinary getter functions with optional GPIOLI=
B:
> +  some open coding of error handling should be expected when you do this=
.
>
>  All the functions that work with the descriptor-based GPIO interface are
>  prefixed with ``gpiod_``. The ``gpio_`` prefix is used for the legacy
>
> ---
> base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
> change-id: 20231002-gpiodoc-cf9430641b91
>
> Best regards,
> --
> Linus Walleij <linus.walleij@linaro.org>
>

Applied, thanks!

Bart