DP_PIPE_SEL
intel_dp->DP |= DP_PIPE_SEL(crtc->pipe);
intel_dp->DP |= DP_PORT_EN | DP_PIPE_SEL(PIPE_A) |
(val & DP_PIPE_SEL_MASK) == DP_PIPE_SEL(PIPE_A))
val |= DP_PIPE_SEL(PIPE_A);
DP |= DP_PIPE_SEL(pipe);