linux-kernel - Re: [PATCH v2] nvmem: meson-efuse: fix function pointer type mismatch

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Message-ID: <CAFhGd8oQ5jh21U4SG3aN5eZJ5h+Ywk4WLFa0yPz8bquFmA1mag@mail.gmail.com>
Date: Fri, 16 Feb 2024 10:58:58 -0800
From: Justin Stitt <justinstitt@...gle.com>
To: Jerome Brunet <jbrunet@...libre.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>, Arnd Bergmann <arnd@...db.de>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Kevin Hilman <khilman@...libre.com>, 
	Martin Blumenstingl <martin.blumenstingl@...glemail.com>, Nathan Chancellor <nathan@...nel.org>, 
	Nick Desaulniers <ndesaulniers@...gle.com>, Bill Wendling <morbo@...gle.com>, 
	Jernej Skrabec <jernej.skrabec@...il.com>, linux-arm-kernel@...ts.infradead.org, 
	linux-amlogic@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	llvm@...ts.linux.dev
Subject: Re: [PATCH v2] nvmem: meson-efuse: fix function pointer type mismatch

Hi,

On Tue, Feb 13, 2024 at 6:28 AM Jerome Brunet <jbrunet@...libre.com> wrote:
>
> clang-16 warns about casting functions to incompatible types, as is done
> here to call clk_disable_unprepare:
>
> drivers/nvmem/meson-efuse.c:78:12: error: cast from 'void (*)(struct clk *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]
>    78 |                                        (void(*)(void *))clk_disable_unprepare,
>
> The pattern of getting, enabling and setting a disable callback for a
> clock can be replaced with devm_clk_get_enabled(), which also fixes
> this warning.
>
> Fixes: 611fbca1c861 ("nvmem: meson-efuse: add peripheral clock")
> Reported-by: Arnd Bergmann <arnd@...db.de>
> Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
> ---
>  drivers/nvmem/meson-efuse.c | 25 +++----------------------

I love negative diffs                                    ^^^^^^^^^^^^^^^

>  1 file changed, 3 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/nvmem/meson-efuse.c b/drivers/nvmem/meson-efuse.c
> index b922df99f9bc..33678d0af2c2 100644
> --- a/drivers/nvmem/meson-efuse.c
> +++ b/drivers/nvmem/meson-efuse.c
> @@ -47,7 +47,6 @@ static int meson_efuse_probe(struct platform_device *pdev)
>         struct nvmem_config *econfig;
>         struct clk *clk;
>         unsigned int size;
> -       int ret;
>
>         sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
>         if (!sm_np) {
> @@ -60,27 +59,9 @@ static int meson_efuse_probe(struct platform_device *pdev)
>         if (!fw)
>                 return -EPROBE_DEFER;
>
> -       clk = devm_clk_get(dev, NULL);
> -       if (IS_ERR(clk)) {
> -               ret = PTR_ERR(clk);
> -               if (ret != -EPROBE_DEFER)
> -                       dev_err(dev, "failed to get efuse gate");
> -               return ret;
> -       }
> -
> -       ret = clk_prepare_enable(clk);
> -       if (ret) {
> -               dev_err(dev, "failed to enable gate");
> -               return ret;
> -       }
> -
> -       ret = devm_add_action_or_reset(dev,
> -                                      (void(*)(void *))clk_disable_unprepare,
> -                                      clk);
> -       if (ret) {
> -               dev_err(dev, "failed to add disable callback");
> -               return ret;
> -       }
> +       clk = devm_clk_get_enabled(dev, NULL);
> +       if (IS_ERR(clk))
> +               return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate");

Wow, this simplified nicely and doesn't make any new helpers (like
Arnd's version).

Reviewed-by: Justin Stitt <justinstitt@...gle.com>

>
>         if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
>                 dev_err(dev, "failed to get max user");
> --
> 2.43.0
>

Thanks
Justin