From eb51c5a103f63b6e9c3f9cebf7b1e2e1056d3119 Mon Sep 17 00:00:00 2001 From: Harry Wentland Date: Fri, 16 Jan 2026 09:39:05 -0500 Subject: [PATCH] drm/amd/display: Set chroma taps to 1 if luma taps are 1 When luma is unscaled we also want chroma to be pixel-perfect. When luma taps are > 1 the result will be a blurred luma plane, even when the image isn't scaled. This makes IGT tests for CSC colorop pass. Assisted-by: Claude: claude-sonnet-4.5 Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Alex Hung Tested-by: Dan Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dpp/dcn10/dcn10_dpp.c | 8 ++++++-- drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c | 8 ++++++-- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/dpp/dcn10/dcn10_dpp.c b/drivers/gpu/drm/amd/display/dc/dpp/dcn10/dcn10_dpp.c index ce91e5d28956..0e70ffc784b1 100644 --- a/drivers/gpu/drm/amd/display/dc/dpp/dcn10/dcn10_dpp.c +++ b/drivers/gpu/drm/amd/display/dc/dpp/dcn10/dcn10_dpp.c @@ -172,10 +172,14 @@ bool dpp1_get_optimal_number_of_taps( scl_data->taps.h_taps_c = in_taps->h_taps_c; if (!dpp->ctx->dc->debug.always_scale) { - if (IDENTITY_RATIO(scl_data->ratios.horz)) + if (IDENTITY_RATIO(scl_data->ratios.horz)) { scl_data->taps.h_taps = 1; - if (IDENTITY_RATIO(scl_data->ratios.vert)) + scl_data->taps.h_taps_c = 1; + } + if (IDENTITY_RATIO(scl_data->ratios.vert)) { scl_data->taps.v_taps = 1; + scl_data->taps.v_taps_c = 1; + } if (IDENTITY_RATIO(scl_data->ratios.horz_c)) scl_data->taps.h_taps_c = 1; if (IDENTITY_RATIO(scl_data->ratios.vert_c)) diff --git a/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c b/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c index c7923531da83..8a146968ee15 100644 --- a/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c +++ b/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c @@ -524,10 +524,14 @@ bool dpp3_get_optimal_number_of_taps( scl_data->taps.v_taps_c = max_taps_c; if (!dpp->ctx->dc->debug.always_scale) { - if (IDENTITY_RATIO(scl_data->ratios.horz)) + if (IDENTITY_RATIO(scl_data->ratios.horz)) { scl_data->taps.h_taps = 1; - if (IDENTITY_RATIO(scl_data->ratios.vert)) + scl_data->taps.h_taps_c = 1; + } + if (IDENTITY_RATIO(scl_data->ratios.vert)) { scl_data->taps.v_taps = 1; + scl_data->taps.v_taps_c = 1; + } if (IDENTITY_RATIO(scl_data->ratios.horz_c)) scl_data->taps.h_taps_c = 1; if (IDENTITY_RATIO(scl_data->ratios.vert_c))