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
References: bsc#1012628
Patch-mainline: 6.2.11
Git-commit: 3f6752b4de41896c7f1609b1585db2080e8150d8

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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 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 8661de32..7fa17283 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2183,6 +2183,8 @@ 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