[PATCH 1/8] drm/amd/display: Workaround wrong HDR colorimetry with some receivers

[Alan Liu]

From: Ilya Bakoulin <Ilya.Bakoulin at amd.com>

[Why]
Some scalers do not pick up color space updates unless the DP link
is disabled/re-enabled which can result in incorrect/washed out
HDR colors in some cases.

[How]
Call set_dpms_on to disable the link, re-train and re-enable with the
updated output color space.

Reviewed-by: Aric Cyr <Aric.Cyr at amd.com>
Acked-by: Alan Liu <HaoPing.Liu at amd.com>
Signed-off-by: Ilya Bakoulin <Ilya.Bakoulin at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 7 +++++++
 drivers/gpu/drm/amd/display/dc/dc.h      | 1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 1fe040544051..7b68ff0f9c4a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -3268,6 +3268,13 @@ static void commit_planes_do_stream_update(struct dc *dc,
 						dc->hwss.prepare_bandwidth(dc, dc->current_state);
 					dc->link_srv->set_dpms_on(dc->current_state, pipe_ctx);
 				}
+			} else if (pipe_ctx->stream->link->wa_flags.blank_stream_on_ocs_change && stream_update->output_color_space
+					&& !stream->dpms_off && dc_is_dp_signal(pipe_ctx->stream->signal)) {
+				/*
+				 * Workaround for firmware issue in some receivers where they don't pick up
+				 * correct output color space unless DP link is disabled/re-enabled
+				 */
+				dc->link_srv->set_dpms_on(dc->current_state, pipe_ctx);
 			}
 
 			if (stream_update->abm_level && pipe_ctx->stream_res.abm) {
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 4424e7abb801..892e3adb99d9 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -1506,6 +1506,7 @@ struct dc_link {
 		/* Forced DPIA into TBT3 compatibility mode. */
 		bool dpia_forced_tbt3_mode;
 		bool dongle_mode_timing_override;
+		bool blank_stream_on_ocs_change;
 	} wa_flags;
 	struct link_mst_stream_allocation_table mst_stream_alloc_table;
 
-- 
2.34.1