From: Jani Nikula jani.nikula@intel.com
commit 13525645e2246ebc8a21bd656248d86022a6ee8f upstream.
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: 0575650077ea ("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.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/drm/display/drm_dp.h | 1 - include/drm/display/drm_dp_helper.h | 5 ++--- 2 files changed, 2 insertions(+), 4 deletions(-)
--- 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
--- 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