From: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Date: Mon, 13 Nov 2017 17:03:53 -0500
Subject: drm/amd/display: set chroma taps to 1 when not scaling
Git-commit: 56a9b95c4d3386a98f69f641dd6018886ed2e9d6
Patch-mainline: v4.15-rc5
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c |    9 +++++++++
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c |    9 ++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c
@@ -900,6 +900,15 @@ bool dcn_validate_bandwidth(
 			v->override_vta_ps[input_idx] = pipe->plane_res.scl_data.taps.v_taps;
 			v->override_hta_pschroma[input_idx] = pipe->plane_res.scl_data.taps.h_taps_c;
 			v->override_vta_pschroma[input_idx] = pipe->plane_res.scl_data.taps.v_taps_c;
+			/*
+			 * Spreadsheet doesn't handle taps_c is one properly,
+			 * need to force Chroma to always be scaled to pass
+			 * bandwidth validation.
+			 */
+			if (v->override_hta_pschroma[input_idx] == 1)
+				v->override_hta_pschroma[input_idx] = 2;
+			if (v->override_vta_pschroma[input_idx] == 1)
+				v->override_vta_pschroma[input_idx] = 2;
 			v->source_scan[input_idx] = (pipe->plane_state->rotation % 2) ? dcn_bw_vert : dcn_bw_hor;
 		}
 		if (v->is_line_buffer_bpp_fixed == dcn_bw_yes)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp.c
@@ -159,11 +159,10 @@ bool dpp_get_optimal_number_of_taps(
 			scl_data->taps.h_taps = 1;
 		if (IDENTITY_RATIO(scl_data->ratios.vert))
 			scl_data->taps.v_taps = 1;
-		/*
-		 * Spreadsheet doesn't handle taps_c is one properly,
-		 * need to force Chroma to always be scaled to pass
-		 * bandwidth validation.
-		 */
+		if (IDENTITY_RATIO(scl_data->ratios.horz_c))
+			scl_data->taps.h_taps_c = 1;
+		if (IDENTITY_RATIO(scl_data->ratios.vert_c))
+			scl_data->taps.v_taps_c = 1;
 	}
 
 	return true;