From 245525543f48cd9eabd2964d8931043e9e3c31cf Mon Sep 17 00:00:00 2001
From: Roman Li <roman.li@amd.com>
Date: Thu, 1 Dec 2022 09:49:23 -0500
Subject: [PATCH] drm/amd/display: Clear MST topology if it fails to resume
Git-commit: 3f6752b4de41896c7f1609b1585db2080e8150d8
Patch-mainline: v6.3-rc1
References: git-fixes

commit 3f6752b4de41896c7f1609b1585db2080e8150d8 upstream.

[Why]
In case of failure to resume MST topology after suspend, an emtpty
mst tree prevents further mst hub detection on the same connector.
That causes the issue with MST hub hotplug after it's been unplug in
suspend.

[How]
Stop topology manager on the connector after detecting DM_MST failure.

Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Jasdeep Dhillon <jdhillon@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: "Limonciello, Mario" <Mario.Limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 050e7a52c8f6..6c5ea99223ba 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2175,6 +2175,8 @@ static int detect_mst_link_for_all_connectors(struct drm_device *dev)
 				DRM_ERROR("DM_MST: Failed to start MST\n");
 				aconnector->dc_link->type =
 					dc_connection_single;
+				ret = dm_helpers_dp_mst_stop_top_mgr(aconnector->dc_link->ctx,
+								     aconnector->dc_link);
 				break;
 			}
 		}
-- 
2.35.3