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

[Jesse Barnes]

On 10/29/2015 12:25 PM, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at 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 at 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 at virtuousgeek.org>