[Why] Under DP daisy chain scenario as below: Src - Monitor_1 - Monitor_2 If unplug 2nd Monitor_2 and plug in again, observe that Monitor_1 doesn't light up. When unplug 2nd monitor, we clear the dc_link->cur_link_settings.lane_count in dm_dp_destroy_mst_connector(). However this link status is a shared data structure by all connected mst monitors. Although the 2nd monitor is gone, this link status should still be retained for other connected mst monitors. Otherwise, when we plug the 2nd monitor in again, we find out that main link is not trained and do link training again. Payload ID Table for Monitor_1 is ruined and we don't reallocate it. [How] In dm_dp_destroy_mst_connector(), only clean the cur_link_settings when we no longer do mst mode. Signed-off-by: Wayne Lin <Wayne.Lin@xxxxxxx> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 2c10352fa514..526f29598403 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -415,7 +415,10 @@ static void dm_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr, aconnector->dc_sink); dc_sink_release(aconnector->dc_sink); aconnector->dc_sink = NULL; - aconnector->dc_link->cur_link_settings.lane_count = 0; + mutex_lock(&mgr->lock); + if (!mgr->mst_state) + aconnector->dc_link->cur_link_settings.lane_count = 0; + mutex_unlock(&mgr->lock); } drm_connector_unregister(connector); -- 2.17.1 _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
