drm/amd/display: Workaround wrong HDR colorimetry with some receivers

[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@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Ilya Bakoulin <Ilya.Bakoulin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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) {

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;