drm_atomic_get_old_connector_state
drm_old_conn_state = drm_atomic_get_old_connector_state(state,
drm_atomic_get_old_connector_state(new_state->state, conn);
old_conn_state = drm_atomic_get_old_connector_state(state, connector);
drm_atomic_get_old_connector_state(state, conn);
old_state = drm_atomic_get_old_connector_state(new_state->state, connector);