From: Leo Li <sunpeng.li@xxxxxxx> commit 2a00299e7447395d0898e7c6214817c06a61a8e8 upstream. [Why] drm_atomic_normalize_zpos() can return an error code when there's modeset lock contention. This was being ignored. [How] Bail out of atomic check if normalize_zpos() returns an error. Fixes: b261509952bc ("drm/amd/display: Fix double cursor on non-video RGB MPO") Signed-off-by: Leo Li <sunpeng.li@xxxxxxx> Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@xxxxxxxxx> Reviewed-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -10889,7 +10889,11 @@ static int amdgpu_dm_atomic_check(struct * `dcn10_can_pipe_disable_cursor`). By now, all modified planes are in * atomic state, so call drm helper to normalize zpos. */ - drm_atomic_normalize_zpos(dev, state); + ret = drm_atomic_normalize_zpos(dev, state); + if (ret) { + drm_dbg(dev, "drm_atomic_normalize_zpos() failed\n"); + goto fail; + } /* Remove exiting planes if they are modified */ for_each_oldnew_plane_in_state_reverse(state, plane, old_plane_state, new_plane_state, i) {