Re: [PATCH 04/14] drm/i915: Enable PCH FIFO underruns later on HSW+

Jesse Barnes
2015-10-29T19:33:50Z

On 10/29/2015 12:25 PM, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> As we did for ILK/SNB/IVB, move the PCH FIFO underrun enable to happen
> after the encoder enable on HSW+. And again, for symmetry, move the
> the disable to happen before encoder disable.
>
> I've left out the vblank wait before the enable here because I don't
> know if it's needed or not. Actually I don't know if this entire
> change is needed as I don't have a HSW/BDW with VGA output.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/i915/intel_display.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index d5cb899..4fc3d24 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4971,11 +4971,8 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
> encoder->pre_enable(encoder);
> }
>
> - if (intel_crtc->config->has_pch_encoder) {
> - intel_set_pch_fifo_underrun_reporting(dev_priv, TRANSCODER_A,
> - true);
> + if (intel_crtc->config->has_pch_encoder)
> dev_priv->display.fdi_link_train(crtc);
> - }
>
> if (!is_dsi)
> intel_ddi_enable_pipe_clock(intel_crtc);
> @@ -5012,6 +5009,10 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
> intel_opregion_notify_encoder(encoder, true);
> }
>
> + if (intel_crtc->config->has_pch_encoder)
> + intel_set_pch_fifo_underrun_reporting(dev_priv, TRANSCODER_A,
> + true);
> +
> /* If we change the relative order between pipe/planes enabling, we need
> * to change the workaround. */
> hsw_workaround_pipe = pipe_config->hsw_workaround_pipe;
> @@ -5096,6 +5097,10 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
> enum transcoder cpu_transcoder = intel_crtc->config->cpu_transcoder;
> bool is_dsi = intel_pipe_has_type(intel_crtc, INTEL_OUTPUT_DSI);
>
> + if (intel_crtc->config->has_pch_encoder)
> + intel_set_pch_fifo_underrun_reporting(dev_priv, TRANSCODER_A,
> + false);
> +
> for_each_encoder_on_crtc(dev, crtc, encoder) {
> intel_opregion_notify_encoder(encoder, false);
> encoder->disable(encoder);
> @@ -5104,9 +5109,6 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
> drm_crtc_vblank_off(crtc);
> assert_vblank_disabled(crtc);
>
> - if (intel_crtc->config->has_pch_encoder)
> - intel_set_pch_fifo_underrun_reporting(dev_priv, TRANSCODER_A,
> - false);
> intel_disable_pipe(intel_crtc);
>
> if (intel_crtc->config->dp_encoder_is_mst)
>

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>