From fca67e1c4b8ca5bf1bbaefcf8f0f086b6c105279 Mon Sep 17 00:00:00 2001
From: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Date: Mon, 30 Aug 2021 14:01:10 -0400
Subject: [PATCH] drm/amd/display: Link training retry fix for abort case
Git-commit: 71ae30997a8f1791835167d3ceb8d1fab32407db
Patch-mainline: v5.15-rc2
References: stable-5.14.9

[ Upstream commit 71ae30997a8f1791835167d3ceb8d1fab32407db ]

[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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@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 a6d0fd24fd02..83ef72a3ebf4 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
@@ -1849,9 +1849,13 @@ 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.
-- 
2.26.2