From: Roman Li <roman.li@xxxxxxx> 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@xxxxxxx> Acked-by: Jasdeep Dhillon <jdhillon@xxxxxxx> Signed-off-by: Roman Li <roman.li@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: "Limonciello, Mario" <Mario.Limonciello@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++ 1 file changed, 2 insertions(+) --- 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_conne 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; } }