From bdc8fdc04f0d1c81d3b7a5ca1c8c80abcc907041 Mon Sep 17 00:00:00 2001
From: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Date: Mon, 30 Aug 2021 14:01:10 -0400
Subject: drm/amd/display: Link training retry fix for abort case
Git-commit: 71ae30997a8f1791835167d3ceb8d1fab32407db
Patch-mainline: v5.15-rc2
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

[Why]
If link training is aborted, it shall be retried if sink is present.

[How]
Check hpd status to find out whether sink is present or not. If sink is
present, then link training shall be tried again with same settings.
Otherwise, link training shall be aborted.

Reviewed-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Acked-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 330edd666b7d..ceda98a63ff3 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1840,9 +1840,13 @@ bool perform_link_training_with_retries(
 		dp_disable_link_phy(link, signal);
 
 		/* Abort link training if failure due to sink being unplugged. */
-		if (status == LINK_TRAINING_ABORT)
-			break;
-		else if (do_fallback) {
+		if (status == LINK_TRAINING_ABORT) {
+			enum dc_connection_type type = dc_connection_none;
+
+			dc_link_detect_sink(link, &type);
+			if (type == dc_connection_none)
+				break;
+		} else if (do_fallback) {
 			decide_fallback_link_setting(*link_setting, &current_setting, status);
 			/* Fail link training if reduced link bandwidth no longer meets
 			 * stream requirements.
-- 
2.38.1