[Intel-gfx] [PATCH v10 2/2] drm/i915: Allow "max bpc" property to limit pipe_bpp

[Radhakrishna Sripada]

On Mon, Oct 01, 2018 at 04:48:01PM +0300, Ville Syrjälä wrote:
> On Mon, Sep 24, 2018 at 02:08:15PM -0700, Radhakrishna Sripada wrote:
> > Use the newly added "max bpc" connector property to limit pipe bpp.
> > 
> > V3: Use drm_connector_state to access the "max bpc" property
> > V4: Initialize the drm property, add suuport to DP(Ville)
> > V5: Use the property in the connector and fix CI failure(Ville)
> > V6: Use the core function to attach max_bpc property, remove the redundant
> >     clamping of pipe bpp based on connector info
> > V7: Fix Checkpatch warnings
> > V9: Cleanup connected_sink_max_bpp and fix initial value in DP(Ville)
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: Kishore Kadiyala <kishore.kadiyala at intel.com>
> > Cc: Manasi Navare <manasi.d.navare at intel.com>
> > Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 48 +++++++++++++++++++++---------------
> >  drivers/gpu/drm/i915/intel_dp.c      |  4 +++
> >  drivers/gpu/drm/i915/intel_hdmi.c    |  5 ++++
> >  3 files changed, 37 insertions(+), 20 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 931898013506..057abfd77cc3 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -10839,30 +10839,38 @@ static void intel_modeset_update_connector_atomic_state(struct drm_device *dev)
> >  	drm_connector_list_iter_end(&conn_iter);
> >  }
> >  
> > -static void
> > -connected_sink_compute_bpp(struct intel_connector *connector,
> > -			   struct intel_crtc_state *pipe_config)
> > +static int
> > +connected_sink_max_bpp(const struct drm_connector_state *conn_state,
> > +		       struct intel_crtc_state *pipe_config)
> >  {
> > -	const struct drm_display_info *info = &connector->base.display_info;
> > -	int bpp = pipe_config->pipe_bpp;
> > +	int bpp;
> > +	struct drm_display_info *info = &conn_state->connector->display_info;
> >  
> > -	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] checking for sink bpp constrains\n",
> > -		      connector->base.base.id,
> > -		      connector->base.name);
> > +	bpp = min(pipe_config->pipe_bpp, conn_state->max_bpc * 3);
> 
> Needs a check to make sure the connector has the property.
We do make a check for the connector property in the drm core. In the absence 
of the property, conn_state->max_bpc carries the limit imposed from 
connector->display_info.bpc and would be requiring the codepath below.

Thoughts?

-- Radhakrishna Sripada
> 
> >  
> > -	/* Don't use an invalid EDID bpc value */
> > -	if (info->bpc != 0 && info->bpc * 3 < bpp) {
> > -		DRM_DEBUG_KMS("clamping display bpp (was %d) to EDID reported max of %d\n",
> > -			      bpp, info->bpc * 3);
> > -		pipe_config->pipe_bpp = info->bpc * 3;
> > +	switch (conn_state->max_bpc) {
> > +	case 6 ... 7:
> > +		pipe_config->pipe_bpp = 6 * 3;
> > +	case 8 ... 9:
> > +		pipe_config->pipe_bpp = 8 * 3;
> > +		break;
> > +	case 10 ... 11:
> > +		pipe_config->pipe_bpp = 10 * 3;
> > +		break;
> > +	case 12:
> > +		pipe_config->pipe_bpp = 12 * 3;
> > +		break;
> > +	default:
> > +		return -EINVAL;
> >  	}
> >  
> > -	/* Clamp bpp to 8 on screens without EDID 1.4 */
> > -	if (info->bpc == 0 && bpp > 24) {
> > -		DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of 24\n",
> > -			      bpp);
> > -		pipe_config->pipe_bpp = 24;
> > +	if (bpp != pipe_config->pipe_bpp) {
> > +		DRM_DEBUG_KMS("Limiting display bpp to %d instead of requested "
> > +			      "bpp %d, Edid bpp %d\n", bpp, 3 * info->bpc,
> > +			      3 * conn_state->max_requested_bpc);
> 
> The format string doesn't seem to match the arguments.
> 
> > +		pipe_config->pipe_bpp = bpp;
> >  	}
> > +	return 0;
> >  }
> >  
> >  static int
> > @@ -10893,8 +10901,8 @@ compute_baseline_pipe_bpp(struct intel_crtc *crtc,
> >  		if (connector_state->crtc != &crtc->base)
> >  			continue;
> >  
> > -		connected_sink_compute_bpp(to_intel_connector(connector),
> > -					   pipe_config);
> > +		if (connected_sink_max_bpp(connector_state, pipe_config) < 0)
> > +			return -EINVAL;
> >  	}
> >  
> >  	return bpp;
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 6b4c19123f2a..d8e128e771a1 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -5719,6 +5719,10 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
> >  		intel_attach_force_audio_property(connector);
> >  
> >  	intel_attach_broadcast_rgb_property(connector);
> > +	if (HAS_GMCH_DISPLAY(dev_priv))
> > +		drm_connector_attach_max_bpc_property(connector, 6, 10);
> > +	else if (INTEL_GEN(dev_priv) >= 5)
> > +		drm_connector_attach_max_bpc_property(connector, 6, 12);
> >  
> >  	if (intel_dp_is_edp(intel_dp)) {
> >  		u32 allowed_scalers;
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> > index a2dab0b6bde6..2b432c7e4f8a 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -2109,11 +2109,16 @@ static const struct drm_encoder_funcs intel_hdmi_enc_funcs = {
> >  static void
> >  intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *connector)
> >  {
> > +	struct drm_i915_private *dev_priv = to_i915(connector->dev);
> > +
> >  	intel_attach_force_audio_property(connector);
> >  	intel_attach_broadcast_rgb_property(connector);
> >  	intel_attach_aspect_ratio_property(connector);
> >  	drm_connector_attach_content_type_property(connector);
> >  	connector->state->picture_aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
> > +
> > +	if (!HAS_GMCH_DISPLAY(dev_priv))
> > +		drm_connector_attach_max_bpc_property(connector, 8, 12);
> >  }
> >  
> >  /*
> > -- 
> > 2.9.3
> 
> -- 
> Ville Syrjälä
> Intel