drm/dsc: fix drm_edp_dsc_sink_output_bpp() DPCD high byte usage

[ Upstream commit 1352564 ] The operator precedence between << and & is wrong, leading to the high byte being completely ignored. For example, with the 6.4 format, 32 becomes 0 and 24 becomes 8. Fix it, and remove the slightly confusing and unnecessary DP_DSC_MAX_BITS_PER_PIXEL_HI_SHIFT macro while at it. Fixes: 0575650 ("drm/dp: DRM DP helper/macros to get DP sink DSC parameters") Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> Cc: Manasi Navare <navaremanasi@google.com> Cc: Anusha Srivatsa <anusha.srivatsa@intel.com> Cc: <stable@vger.kernel.org> # v5.0+ Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230406134615.1422509-1-jani.nikula@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
xanmod · May 17, 2023 · 98643c9 · 98643c9
1 parent f95a600
commit 98643c9
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Showing 2 changed files with 2 additions and 4 deletions.
diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h
@@ -286,7 +286,6 @@
 
 #define DP_DSC_MAX_BITS_PER_PIXEL_HI        0x068   /* eDP 1.4 */
 # define DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK  (0x3 << 0)
-# define DP_DSC_MAX_BITS_PER_PIXEL_HI_SHIFT 8
 # define DP_DSC_MAX_BPP_DELTA_VERSION_MASK  0x06
 # define DP_DSC_MAX_BPP_DELTA_AVAILABILITY  0x08
 

diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h
@@ -181,9 +181,8 @@ static inline u16
 drm_edp_dsc_sink_output_bpp(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
 {
 	return dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
-		(dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
-		 DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK <<
-		 DP_DSC_MAX_BITS_PER_PIXEL_HI_SHIFT);
+		((dsc_dpcd[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] &
+		  DP_DSC_MAX_BITS_PER_PIXEL_HI_MASK) << 8);
 }
 
 static inline u32