DP_PSR_STATUS
ret = drm_dp_dpcd_readb(&dp->aux, DP_PSR_STATUS, &sink);
ret = drm_dp_dpcd_readb(&dp->aux, DP_PSR_STATUS, &sink);
val = drm_dp_dpcd_readb(&dp->aux, DP_PSR_STATUS, &status);
DP_SINK_DEVICE_PR_AND_FRAME_LOCK_STATUS : DP_PSR_STATUS;