drm/amd/display: Clear MST topology if it fails to resume

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>

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 050e7a52c8f62b26ad454a27e0a0636875fc5c5e..6c5ea99223bab5e671698e3f20ea984445083786 100644 (file)
--- 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;
                        }
                }