diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 33cf197df7534..9c8718366cc2a 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4137,6 +4137,12 @@ static void ironlake_pch_enable(struct drm_crtc *crtc) I915_WRITE(FDI_RX_TUSIZE1(pipe), I915_READ(PIPE_DATA_M1(pipe)) & TU_SIZE_MASK); + /* + * Sometimes spurious CPU pipe underruns happen during FDI + * training, at least with VGA+HDMI cloning. Suppress them. + */ + intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false); + /* For PCH output, training FDI link */ dev_priv->display.fdi_link_train(crtc); @@ -4170,6 +4176,8 @@ static void ironlake_pch_enable(struct drm_crtc *crtc) intel_fdi_normal_train(crtc); + intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true); + /* For PCH DP, enable TRANS_DP_CTL */ if (HAS_PCH_CPT(dev) && intel_crtc->config->has_dp_encoder) { const struct drm_display_mode *adjusted_mode = @@ -5062,12 +5070,22 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc) drm_crtc_vblank_off(crtc); assert_vblank_disabled(crtc); + /* + * Sometimes spurious CPU pipe underruns happen when the + * pipe is already disabled, but FDI RX/TX is still enabled. + * Happens at least with VGA+HDMI cloning. Suppress them. + */ + if (intel_crtc->config->has_pch_encoder) + intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false); + intel_disable_pipe(intel_crtc); ironlake_pfit_disable(intel_crtc, false); - if (intel_crtc->config->has_pch_encoder) + if (intel_crtc->config->has_pch_encoder) { ironlake_fdi_disable(crtc); + intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true); + } for_each_encoder_on_crtc(dev, crtc, encoder) if (encoder->post_disable)