RE: [PATCH] drm/amd/display: Don't take the address of skip_scdc_overwrite in dc_link_detect_helper
From: Liu, Zhan
Date: Fri Feb 14 2020 - 11:01:11 EST
> -----Original Message-----
> From: dri-devel <dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of
> Nathan Chancellor
> Sent: 2020/February/14, Friday 1:30 AM
> To: Wentland, Harry <Harry.Wentland@xxxxxxx>; Li, Sun peng (Leo)
> <Sunpeng.Li@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; Koenig, Christian
> <Christian.Koenig@xxxxxxx>; Zhou, David(ChunMing)
> <David1.Zhou@xxxxxxx>
> Cc: clang-built-linux@xxxxxxxxxxxxxxxx; Nathan Chancellor
> <natechancellor@xxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; amd-
> gfx@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] drm/amd/display: Don't take the address of
> skip_scdc_overwrite in dc_link_detect_helper
>
> Clang warns:
>
> ../drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:980:36:
> warning: address of 'sink->edid_caps.panel_patch.skip_scdc_overwrite'
> will always evaluate to 'true' [-Wpointer-bool-conversion]
> if (&sink->edid_caps.panel_patch.skip_scdc_overwrite)
> ~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
> 1 warning generated.
>
> This is probably not what was intended so remove the address of operator,
> which matches how skip_scdc_overwrite is handled in the rest of the driver.
>
> While we're here, drop an extra newline after this if block.
>
> Fixes: a760fc1bff03 ("drm/amd/display: add monitor patch to disable SCDC
> read/write")
> Link:
> https://github.com/ClangBuiltLinux/linux/issues/879
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Thank you!
Reviewed-by: Zhan Liu <zhan.liu@xxxxxxx>
> ---
>
> As an aside, I don't see skip_scdc_overwrite assigned a value anywhere, is
> this working as intended?
>
> drivers/gpu/drm/amd/display/dc/core/dc_link.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> index 24d99849be5e..a3bfa05c545e 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
> @@ -977,10 +977,9 @@ static bool dc_link_detect_helper(struct dc_link
> *link,
> if ((prev_sink != NULL) && ((edid_status == EDID_THE_SAME)
> || (edid_status == EDID_OK)))
> same_edid = is_same_edid(&prev_sink->dc_edid,
> &sink->dc_edid);
>
> - if (&sink->edid_caps.panel_patch.skip_scdc_overwrite)
> + if (sink->edid_caps.panel_patch.skip_scdc_overwrite)
> link->ctx->dc->debug.hdmi20_disable = true;
>
> -
> if (link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT
> &&
> sink_caps.transaction_type ==
> DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
> /*
> --
> 2.25.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.
> freedesktop.org%2Fmailman%2Flistinfo%2Fdri-
> devel&data=02%7C01%7Czhan.liu%40amd.com%7Cb0b05e8e1c944b85
> 0cc108d7b12508b4%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7
> C637172644928182374&sdata=OfX%2BPBPCkFt8Elo12VfVBg6Ecnui7Vh
> hZwQFaKy5eyM%3D&reserved=0