drm/amd/display: Fix MST reboot/poweroff sequence

[Why]

drm_dp_mst_topology_mgr_suspend() is added into the new reboot
sequence, which disables the UP request at the beginning.
Therefore sideband messages are blocked.

[How]

Finish MST sideband message transaction before UP request is
suppressed.

Signed-off-by: Leo (Hanghong) Ma <hanghong.ma@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.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 0b392bf..5296b8f 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -786,12 +786,13 @@ static int dm_suspend(void *handle)
        struct amdgpu_display_manager *dm = &adev->dm;
        int ret = 0;
 
+       WARN_ON(adev->dm.cached_state);
+       adev->dm.cached_state = drm_atomic_helper_suspend(adev->ddev);
+
        s3_handle_mst(adev->ddev, true);
 
        amdgpu_dm_irq_suspend(adev);
 
-       WARN_ON(adev->dm.cached_state);
-       adev->dm.cached_state = drm_atomic_helper_suspend(adev->ddev);
 
        dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D3);