Commit bc068194 authored by Wayne Lin's avatar Wayne Lin Committed by Alex Deucher
Browse files

drm/amd/display: Don't write DP_MSTM_CTRL after LT 



[Why]
Observe after suspend/resme, we can't light up mst monitors under specific
mst hub. The reason is that driver still writes DPCD DP_MSTM_CTRL after LT.
It's forbidden even we write the same value for that dpcd register.

[How]
We already resume the mst branch device dpcd settings during
resume_mst_branch_status(). Leverage drm_dp_mst_topology_queue_probe() to
only probe the topology, not calling drm_dp_mst_topology_mgr_resume() which
will set DP_MSTM_CTRL as well.

Reviewed-by: default avatarJerry Zuo <jerry.zuo@amd.com>
Signed-off-by: default avatarWayne Lin <Wayne.Lin@amd.com>
Signed-off-by: default avatarZaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent caccee7b

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+4 −12
Original line number Diff line number Diff line
@@ -3170,8 +3170,7 @@ static int dm_resume(struct amdgpu_ip_block *ip_block) 
	struct dm_atomic_state *dm_state = to_dm_atomic_state(dm->atomic_obj.state);

	enum dc_connection_type new_connection_type = dc_connection_none;

	struct dc_state *dc_state;

	int i, r, j, ret;

	bool need_hotplug = false;

	int i, r, j;

	struct dc_commit_streams_params commit_params = {};



	if (dm->dc->caps.ips_support) {
@@ -3360,23 +3359,16 @@ static int dm_resume(struct amdgpu_ip_block *ip_block) 
		    aconnector->mst_root)

			continue;



		ret = drm_dp_mst_topology_mgr_resume(&aconnector->mst_mgr, true);



		if (ret < 0) {

			dm_helpers_dp_mst_stop_top_mgr(aconnector->dc_link->ctx,

					aconnector->dc_link);

			need_hotplug = true;

		}

		drm_dp_mst_topology_queue_probe(&aconnector->mst_mgr);

	}

	drm_connector_list_iter_end(&iter);



	if (need_hotplug)

		drm_kms_helper_hotplug_event(ddev);



	amdgpu_dm_irq_resume_late(adev);



	amdgpu_dm_smu_write_watermarks_table(adev);



	drm_kms_helper_hotplug_event(ddev);



	return 0;

}