From e6d14df74064fc65c6367d4c717e016c9d99be59 Mon Sep 17 00:00:00 2001 From: Krunoslav Kovac Date: Fri, 9 Aug 2019 17:16:18 -0400 Subject: drm/amd/display: Subsample mode suboptimal for YCbCr4:2:2 [Why&How] Driver defaults to 1-tap subsample mode for 4:2:2. DCE11.2 added 3-tap. The policy is: DCE8-DCE11 - change to 2-tap, it's better than 1-tap. DCE11.2+ - use 3-tap Note that 4:2:0 was added in DCE11.2 and already uses 3-tap always. Note 2 is that DCE not covered on Linux, only DCN+ Signed-off-by: Krunoslav Kovac Reviewed-by: Charlene Liu Acked-by: Bhawanpreet Lakha Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.c | 5 ++++- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.h | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.c index e9ebbbe256b4..02c8a3e0b533 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.c @@ -168,7 +168,10 @@ static void opp1_set_pixel_encoding( REG_UPDATE(FMT_CONTROL, FMT_PIXEL_ENCODING, 0); break; case PIXEL_ENCODING_YCBCR422: - REG_UPDATE(FMT_CONTROL, FMT_PIXEL_ENCODING, 1); + REG_UPDATE_3(FMT_CONTROL, + FMT_PIXEL_ENCODING, 1, + FMT_SUBSAMPLING_MODE, 2, + FMT_CBCR_BIT_REDUCTION_BYPASS, 0); break; case PIXEL_ENCODING_YCBCR420: REG_UPDATE(FMT_CONTROL, FMT_PIXEL_ENCODING, 2); diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.h b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.h index 0f10adea000c..2c0ecfa5a643 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.h +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_opp.h @@ -116,6 +116,8 @@ type FMT_RAND_G_SEED; \ type FMT_RAND_B_SEED; \ type FMT_PIXEL_ENCODING; \ + type FMT_SUBSAMPLING_MODE; \ + type FMT_CBCR_BIT_REDUCTION_BYPASS; \ type FMT_CLAMP_DATA_EN; \ type FMT_CLAMP_COLOR_FORMAT; \ type FMT_DYNAMIC_EXP_EN; \ -- cgit v1.2.3-59-g8ed1b