GEN8_PIPE_VBLANK
if (iir & GEN8_PIPE_VBLANK)
bdw_enable_pipe_irq(dev_priv, pipe, GEN8_PIPE_VBLANK);
bdw_disable_pipe_irq(dev_priv, pipe, GEN8_PIPE_VBLANK);
uint32_t extra_ier = GEN8_PIPE_VBLANK | GEN8_PIPE_FIFO_UNDERRUN;
de_pipe_enables = de_pipe_masked | GEN8_PIPE_VBLANK |