[Intel-gfx] [PATCH v3 1/3] drm/i915/display: Compute has_drrs after compute has_psr

[Anshuman Gupta]

On 2020-08-26 at 22:17:38 +0530, Souza, Jose wrote:
> On Wed, 2020-08-26 at 12:56 +0530, Anshuman Gupta wrote:
> > On 2020-08-25 at 10:13:29 -0700, José Roberto de Souza wrote:
> > > DRRS and PSR can't be enable together, so giving preference to PSR
> > > as it allows more power-savings by complete shutting down display,
> > > so to guarantee this, it should compute DRRS state after compute PSR.
> > > 
> > > Cc: Srinivas K <
> > > srinivasx.k at intel.com
> > > >
> > > Cc: Hariom Pandey <
> > > hariom.pandey at intel.com
> > > >
> > > Reviewed-by: Anshuman Gupta <
> > > anshuman.gupta at intel.com
> > > >
> > > Signed-off-by: José Roberto de Souza <
> > > jose.souza at intel.com
> > > >
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_dp.c | 52 +++++++++++++++----------
> > >  1 file changed, 32 insertions(+), 20 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 79c27f91f42c..a08d03c61b02 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -2575,6 +2575,34 @@ intel_dp_compute_hdr_metadata_infoframe_sdp(struct intel_dp *intel_dp,
> > >  		intel_hdmi_infoframe_enable(HDMI_PACKET_TYPE_GAMUT_METADATA);
> > >  }
> > >  
> > > +static void
> > > +intel_dp_drrs_compute_config(struct intel_dp *intel_dp,
> > > +			     struct intel_crtc_state *pipe_config,
> > > +			     int output_bpp, bool constant_n)
> > > +{
> > > +	struct intel_connector *intel_connector = intel_dp->attached_connector;
> > > +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > > +
> > > +	/*
> > > +	 * DRRS and PSR can't be enable together, so giving preference to PSR
> > > +	 * as it allows more power-savings by complete shutting down display,
> > > +	 * so to guarantee this, intel_dp_drrs_compute_config() must be called
> > > +	 * after intel_psr_compute_config().
> > > +	 */
> > > +	if (pipe_config->has_psr)
> > > +		return;
> > > +
> > > +	if (!intel_connector->panel.downclock_mode ||
> > > +	    dev_priv->drrs.type != SEAMLESS_DRRS_SUPPORT)
> > > +		return;
> > > +
> > > +	pipe_config->has_drrs = true;
> > > +	intel_link_compute_m_n(output_bpp, pipe_config->lane_count,
> > > +			       intel_connector->panel.downclock_mode->clock,
> > > +			       pipe_config->port_clock, &pipe_config->dp_m2_n2,
> > > +			       constant_n, pipe_config->fec_enable);
> > > +}
> > > +
> > >  int
> > >  intel_dp_compute_config(struct intel_encoder *encoder,
> > >  			struct intel_crtc_state *pipe_config,
> > > @@ -2605,7 +2633,6 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> > >  	if (ret)
> > >  		return ret;
> > >  
> > > -	pipe_config->has_drrs = false;
> > 
> > IMHO this assignment is required, i was thinking a case, when a crtc is attached to more than 
> > one connector, suppose first eDP connector supports DRRS from panel.downclock_mode and
> > drrs.type but another DP connector won't support it in that case has_drrs will be still
> > true.
> > Please correct me if i am wrong here. 
> 
> i915 only supports one connector per pipe/CRTC, if that was the case all other flags in intel_crtc_state would also have the same behaviour as
> has_drrs.
Actually once on kabylake i had witnessed this use case when a CRTC was attached to multiple connectors, AFAIU theortically also 
it seems possible as intel_modeset_pipe_config iterate for each connector in state for a given crtc i.e (connector_state->crtc == crtc)
and call encoder->compute_config().
If you are sure above case can't happen for drrs you can use my RB.
Applicable for [PATCH 3/3] of this series,
Reviewed-by: Anshuman Gupta <anshuman.gupta at intel.com>
> 
> > Thanks,
> > Anshuman Gupta.
> > >  	if (!intel_dp_port_has_audio(dev_priv, port))
> > >  		pipe_config->has_audio = false;
> > >  	else if (intel_conn_state->force_audio == HDMI_AUDIO_AUTO)
> > > @@ -2657,21 +2684,12 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> > >  			       &pipe_config->dp_m_n,
> > >  			       constant_n, pipe_config->fec_enable);
> > >  
> > > -	if (intel_connector->panel.downclock_mode != NULL &&
> > > -		dev_priv->drrs.type == SEAMLESS_DRRS_SUPPORT) {
> > > -			pipe_config->has_drrs = true;
> > > -			intel_link_compute_m_n(output_bpp,
> > > -					       pipe_config->lane_count,
> > > -					       intel_connector->panel.downclock_mode->clock,
> > > -					       pipe_config->port_clock,
> > > -					       &pipe_config->dp_m2_n2,
> > > -					       constant_n, pipe_config->fec_enable);
> > > -	}
> > > -
> > >  	if (!HAS_DDI(dev_priv))
> > >  		intel_dp_set_clock(encoder, pipe_config);
> > >  
> > >  	intel_psr_compute_config(intel_dp, pipe_config);
> > > +	intel_dp_drrs_compute_config(intel_dp, pipe_config, output_bpp,
> > > +				     constant_n);
> > >  	intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
> > >  	intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp, pipe_config, conn_state);
> > >  
> > > @@ -7730,16 +7748,10 @@ void intel_edp_drrs_enable(struct intel_dp *intel_dp,
> > >  {
> > >  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > >  
> > > -	if (!crtc_state->has_drrs) {
> > > -		drm_dbg_kms(&dev_priv->drm, "Panel doesn't support DRRS\n");
> > > +	if (!crtc_state->has_drrs)
> > >  		return;
> > > -	}
> > >  
> > > -	if (dev_priv->psr.enabled) {
> > > -		drm_dbg_kms(&dev_priv->drm,
> > > -			    "PSR enabled. Not enabling DRRS.\n");
> > > -		return;
> > > -	}
> > > +	drm_dbg_kms(&dev_priv->drm, "Enabling DRRS\n");
> > >  
> > >  	mutex_lock(&dev_priv->drrs.mutex);
> > >  	if (dev_priv->drrs.dp) {
> > > -- 
> > > 2.28.0
> > >