From: Manasi Navare Date: Fri, 4 Dec 2020 20:58:04 +0000 (-0800) Subject: drm/i915/display/dp: Compute the correct slice count for VDSC on DP X-Git-Tag: v5.10~18^2~1^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f6cbe49be65ed800863ac5ba695555057363f9c2;p=thirdparty%2Fkernel%2Flinux.git drm/i915/display/dp: Compute the correct slice count for VDSC on DP This patch fixes the slice count computation algorithm for calculating the slice count based on Peak pixel rate and the max slice width allowed on the DSC engines. We need to ensure slice count > min slice count req as per DP spec based on peak pixel rate and that it is greater than min slice count based on the max slice width advertised by DPCD. So use max of these two. In the prev patch we were using min of these 2 causing it to violate the max slice width limitation causing a blank screen on 8K@60. Fixes: d9218c8f6cf4 ("drm/i915/dp: Add helpers for Compressed BPP and Slice Count for DSC") Cc: Ankit Nautiyal Cc: Jani Nikula Cc: # v5.0+ Signed-off-by: Manasi Navare Reviewed-by: Ankit Nautiyal Link: https://patchwork.freedesktop.org/patch/msgid/20201204205804.25225-1-manasi.d.navare@intel.com (cherry picked from commit d371d6ea92ad2a47f42bbcaa786ee5f6069c9c14) Signed-off-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index bf1e9cf1c0f3f..9bc59fd2f95f5 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -573,7 +573,7 @@ static u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp, return 0; } /* Also take into account max slice width */ - min_slice_count = min_t(u8, min_slice_count, + min_slice_count = max_t(u8, min_slice_count, DIV_ROUND_UP(mode_hdisplay, max_slice_width));