From: Peterson Date: Mon, 23 Sep 2024 14:30:50 +0000 (-0400) Subject: drm/amd/display: Fix low black values by increasing error X-Git-Tag: v6.13-rc1~122^2~15^2~141 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eda7f2e9bb3b6ba16cb19e521b433b22b220c0d0;p=thirdparty%2Fkernel%2Flinux.git drm/amd/display: Fix low black values by increasing error [WHY] Regamma resolution for the first few black levels can have problems for calibration. [HOW] HW LUT is divided into N power-of-2 regions each with K segments. For SDR mode we set min point at 2^-10 and increments of 2^-13. It's generally more than 8-bit SDR needs, but some calibration tools and API use 12-bit curves. The fix shifts starting point to 2^-12 and starting increments at 2^-16. Reviewed-by: Krunoslav Kovac Signed-off-by: Peterson Signed-off-by: Rodrigo Siqueira Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c index eaed5d1c398aa..dcd2cdfe91eb6 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c @@ -365,23 +365,18 @@ bool cm_helper_translate_curve_to_hw_format(struct dc_context *ctx, region_start = -MAX_LOW_POINT; region_end = NUMBER_REGIONS - MAX_LOW_POINT; } else { - /* 11 segments - * segment is from 2^-10 to 2^1 + /* 13 segments + * segment is from 2^-12 to 2^0 * There are less than 256 points, for optimization */ - seg_distr[0] = 3; - seg_distr[1] = 4; - seg_distr[2] = 4; - seg_distr[3] = 4; - seg_distr[4] = 4; - seg_distr[5] = 4; - seg_distr[6] = 4; - seg_distr[7] = 4; - seg_distr[8] = 4; - seg_distr[9] = 4; - seg_distr[10] = 1; - - region_start = -10; + const uint8_t SEG_COUNT = 12; + + for (i = 0; i < SEG_COUNT; i++) + seg_distr[i] = 4; + + seg_distr[SEG_COUNT] = 1; + + region_start = -SEG_COUNT; region_end = 1; } diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_cm_common.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_cm_common.c index f31f0e3abfc0f..1e1038fb04e8d 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_cm_common.c +++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_cm_common.c @@ -140,23 +140,18 @@ bool cm3_helper_translate_curve_to_hw_format( region_start = -MAX_LOW_POINT; region_end = NUMBER_REGIONS - MAX_LOW_POINT; } else { - /* 11 segments - * segment is from 2^-10 to 2^0 + /* 13 segments + * segment is from 2^-12 to 2^0 * There are less than 256 points, for optimization */ - seg_distr[0] = 3; - seg_distr[1] = 4; - seg_distr[2] = 4; - seg_distr[3] = 4; - seg_distr[4] = 4; - seg_distr[5] = 4; - seg_distr[6] = 4; - seg_distr[7] = 4; - seg_distr[8] = 4; - seg_distr[9] = 4; - seg_distr[10] = 1; - - region_start = -10; + const uint8_t SEG_COUNT = 12; + + for (i = 0; i < SEG_COUNT; i++) + seg_distr[i] = 4; + + seg_distr[SEG_COUNT] = 1; + + region_start = -SEG_COUNT; region_end = 1; }