linux-kernel - Re: [PATCH] drm/amd/display: Remove pointless NULL checks in dmub_psr_copy_settings

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Date:   Wed, 4 Mar 2020 13:34:46 -0500
From:   Alex Deucher <alexdeucher@...il.com>
To:     Nathan Chancellor <natechancellor@...il.com>
Cc:     Harry Wentland <harry.wentland@....com>,
        Leo Li <sunpeng.li@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Christian König <christian.koenig@....com>,
        "David (ChunMing) Zhou" <David1.Zhou@....com>,
        clang-built-linux <clang-built-linux@...glegroups.com>,
        Maling list - DRI developers 
        <dri-devel@...ts.freedesktop.org>,
        amd-gfx list <amd-gfx@...ts.freedesktop.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/amd/display: Remove pointless NULL checks in dmub_psr_copy_settings

On Mon, Mar 2, 2020 at 5:43 PM Nathan Chancellor
<natechancellor@...il.com> wrote:
>
> Clang warns:
>
> drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dmub_psr.c:147:31: warning:
> address of 'pipe_ctx->plane_res' will always evaluate to 'true'
> [-Wpointer-bool-conversion]
>         if (!pipe_ctx || !&pipe_ctx->plane_res || !&pipe_ctx->stream_res)
>                          ~ ~~~~~~~~~~^~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dmub_psr.c:147:56: warning:
> address of 'pipe_ctx->stream_res' will always evaluate to 'true'
> [-Wpointer-bool-conversion]
>         if (!pipe_ctx || !&pipe_ctx->plane_res || !&pipe_ctx->stream_res)
>                                                   ~ ~~~~~~~~~~^~~~~~~~~~
> 2 warnings generated.
>
> As long as pipe_ctx is not NULL, the address of members in this struct
> cannot be NULL, which means these checks will always evaluate to false.
>
> Fixes: 4c1a1335dfe0 ("drm/amd/display: Driverside changes to support PSR in DMCUB")
> Link: https://github.com/ClangBuiltLinux/linux/issues/915
> Signed-off-by: Nathan Chancellor <natechancellor@...il.com>

Applied.  Thanks!

Alex

> ---
>  drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
> index 2c932c29f1f9..a9e1c01e9d9b 100644
> --- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
> +++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
> @@ -144,7 +144,7 @@ static bool dmub_psr_copy_settings(struct dmub_psr *dmub,
>                 }
>         }
>
> -       if (!pipe_ctx || !&pipe_ctx->plane_res || !&pipe_ctx->stream_res)
> +       if (!pipe_ctx)
>                 return false;
>
>         // First, set the psr version
> --
> 2.25.1
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

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