Commit 202dc359 authored by Wayne Lin's avatar Wayne Lin Committed by Alex Deucher
Browse files

drm/amd/display: Defer handling mst up request in resume 



[Why]
Like commit ec5fa9fc ("drm/amd/display: Adjust the MST resume flow"), we
want to avoid handling mst topology changes before restoring the old state.
If we enable DP_UP_REQ_EN before calling drm_atomic_helper_resume(), have
changce to handle CSN event first and fire hotplug event before restoring the
cached state.

[How]
Disable mst branch sending up request event before we restoring the cached state.
DP_UP_REQ_EN will be set later when we call drm_dp_mst_topology_mgr_resume().

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarHersen Wu <hersenxs.wu@amd.com>
Signed-off-by: default avatarWayne Lin <wayne.lin@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent ae308e93

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

+0 −1
Original line number Diff line number Diff line
@@ -2429,7 +2429,6 @@ static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr) 


	ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,

				 DP_MST_EN |

				 DP_UP_REQ_EN |

				 DP_UPSTREAM_IS_SRC);

	if (ret < 0) {

		drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");