Commit 13525645 authored by Jani Nikula's avatar Jani Nikula
Browse files

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



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: 05756500 ("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: default avatarJani Nikula <jani.nikula@intel.com>
Reviewed-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230406134615.1422509-1-jani.nikula@intel.com
parent 1b617bc9

include/drm/display/drm_dp.h

+0 −1
Original line number Diff line number Diff line
@@ -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

include/drm/display/drm_dp_helper.h

+2 −3
Original line number Diff line number Diff line
@@ -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