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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Mon, 27 Mar 2023 19:48:06 -0400
Message-ID: <CADnq5_MpPB-V2ZUr7AQDyczuSyJ4=sMCnRSdqEFG9sfBdn1eLQ@mail.gmail.com>
Subject: Re: [PATCH 02/12] drm/amd: Remove unused variable 'value0'
To:     Caio Novais <caionovais@usp.br>
Cc:     amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, Felipe Clark <felipe.clark@amd.com>,
        Wenjing Liu <wenjing.liu@amd.com>,
        =?UTF-8?B?TWHDrXJhIENhbmFs?= <mairacanal@riseup.net>,
        Mario Limonciello <mario.limonciello@amd.com>,
        Jun Lei <Jun.Lei@amd.com>, Charlene Liu <Charlene.Liu@amd.com>,
        Gabe Teeger <gabe.teeger@amd.com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
        Taimur Hassan <Syed.Hassan@amd.com>,
        Aurabindo Pillai <aurabindo.pillai@amd.com>,
        Alvin Lee <alvin.lee2@amd.com>,
        George Shen <George.Shen@amd.com>,
        Hamza Mahfooz <hamza.mahfooz@amd.com>,
        Chaitanya Dhere <chaitanya.dhere@amd.com>,
        Alan Liu <HaoPing.Liu@amd.com>,
        Mukul Joshi <mukul.joshi@amd.com>,
        =?UTF-8?Q?Andr=C3=A9_Almeida?= <andrealmeid@igalia.com>,
        Jingwen Zhu <Jingwen.Zhu@amd.com>,
        Guo Zhengkui <guozhengkui@vivo.com>,
        Leo Li <sunpeng.li@amd.com>, Melissa Wen <mwen@igalia.com>,
        Le Ma <le.ma@amd.com>,
        Jiapeng Chong <jiapeng.chong@linux.alibaba.com>,
        Martin Leung <Martin.Leung@amd.com>,
        Ryan Lin <tsung-hua.lin@amd.com>,
        Brian Chang <Brian.Chang@amd.com>,
        Sung Joon Kim <sungjoon.kim@amd.com>,
        Yifan Zhang <yifan1.zhang@amd.com>,
        Jack Xiao <Jack.Xiao@amd.com>,
        Dillon Varone <Dillon.Varone@amd.com>,
        Tom Chung <chiahsuan.chung@amd.com>,
        Wesley Chalmers <Wesley.Chalmers@amd.com>,
        Qingqing Zhuo <qingqing.zhuo@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>, Zhan Liu <zhan.liu@amd.com>,
        Roman Li <Roman.Li@amd.com>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        Wayne Lin <wayne.lin@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Ethan Wellenreiter <Ethan.Wellenreiter@amd.com>,
        Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>,
        Joshua Ashton <joshua@froggi.es>,
        Hawking Zhang <Hawking.Zhang@amd.com>
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On Mon, Mar 27, 2023 at 7:34=E2=80=AFPM Caio Novais <caionovais@usp.br> wro=
te:
>
> Compiling AMD GPU drivers displays a warning:
>
> drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_link_encoder.c: In f=
unction =E2=80=98dcn10_link_encoder_update_mst_stream_allocation_table=E2=
=80=99:
> drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_link_encoder.c:1222:=
18: warning: variable =E2=80=98value0=E2=80=99 set but not used [-Wunused-b=
ut-set-variable]
>
> Get rid of it by removing the variable.
>
> Signed-off-by: Caio Novais <caionovais@usp.br>
> ---
>  drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c b/=
drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c
> index c4287147b853..81aa1631945a 100644
> --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c
> +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_link_encoder.c
> @@ -1219,7 +1219,6 @@ void dcn10_link_encoder_update_mst_stream_allocatio=
n_table(
>         const struct link_mst_stream_allocation_table *table)
>  {
>         struct dcn10_link_encoder *enc10 =3D TO_DCN10_LINK_ENC(enc);
> -       uint32_t value0 =3D 0;
>         uint32_t value1 =3D 0;
>         uint32_t value2 =3D 0;
>         uint32_t slots =3D 0;
> @@ -1321,8 +1320,6 @@ void dcn10_link_encoder_update_mst_stream_allocatio=
n_table(
>         do {
>                 udelay(10);
>
> -               value0 =3D REG_READ(DP_MSE_SAT_UPDATE);

This reads a register.  Removing it may adversely affect the
programming sequence.  If you want to avoid the set but unused
warning, just drop the assignment, but leave the REG_READ.

Alex

> -
>                 REG_GET(DP_MSE_SAT_UPDATE,
>                                 DP_MSE_SAT_UPDATE, &value1);
>
> --
> 2.40.0
>