From 51e0c9b8f4d6046c887a8ab9dc75cefdff2740d8 Mon Sep 17 00:00:00 2001
From: Xiaodong Yan <Xiaodong.Yan@amd.com>
Date: Sun, 5 Apr 2020 16:40:46 -0400
Subject: drm/amd/display: blank dp stream before power off receiver
Git-commit: c5f5b9d934ba897182ba7159f4d1f1ff06234e3e
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

[why]
power off dp receiver directly cause garbage during hw init

[how]
blank dp stream and then power off receiver

Signed-off-by: Xiaodong Yan <Xiaodong.Yan@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index 1c7f6f7fb7a4..9bed5e885fed 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -1328,6 +1328,14 @@ void dcn10_init_hw(struct dc *dc)
 		uint8_t dpcd_power_state = '\0';
 		enum dc_status status = DC_ERROR_UNEXPECTED;
 
+		/* blank all dp streams before power off receiver,
+		 * this should only impact DP
+		 */
+		for (i = 0; i < dc->res_pool->stream_enc_count; i++) {
+			dc->res_pool->stream_enc[i]->funcs->dp_blank(
+						dc->res_pool->stream_enc[i]);
+		}
+
 		for (i = 0; i < dc->link_count; i++) {
 			if (dc->links[i]->connector_signal != SIGNAL_TYPE_DISPLAY_PORT)
 				continue;
-- 
2.28.0