intel_wait_for_vblank_if_active
intel_wait_for_vblank_if_active(dev_priv, !crtc->pipe);
intel_wait_for_vblank_if_active(dev_priv, PIPE_A);
intel_wait_for_vblank_if_active(dev_priv, PIPE_A);
intel_wait_for_vblank_if_active(dev_priv, PIPE_A);