[Intel-gfx] [PATCH v3 1/2] drm: drm/i915: Add connector property to limit max bpc

Ville Syrjälä ville.syrjala at linux.intel.com
Thu Aug 30 13:38:43 UTC 2018


On Wed, Aug 29, 2018 at 03:57:05PM -0700, Radhakrishna Sripada wrote:
> On Mon, Aug 27, 2018 at 04:31:49PM +0300, Ville Syrjälä wrote:
> > On Fri, Aug 24, 2018 at 06:02:16PM -0700, Radhakrishna Sripada wrote:
> > > At times 12bpc HDMI cannot be driven due to faulty cables, dongles
> > > level shifters etc. To workaround them we may need to drive the output
> > > at a lower bpc. Currently the user space does not have a way to limit
> > > the bpc. The default bpc to be programmed is decided by the driver and
> > > is run against connector limitations.
> > > 
> > > Creating a new connector property "max bpc" in order to limit the bpc
> > > with which the pixels are scanned out. xrandr can make use of this
> > > connector property to make sure that bpc does not exceed the configured value.
> > > This property can be used by userspace to set the bpc.
> > > 
> > > V2: Initialize max_bpc to satisfy kms_properties
> > > V3: Move the property to drm_connector
> > > 
> > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Cc: Kishore Kadiyala <kishore.kadiyala at intel.com>
> > > Cc: Rodrigo Vivi <rodrigo.vivi 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/drm_atomic.c        |  4 ++++
> > >  drivers/gpu/drm/drm_atomic_helper.c |  4 ++++
> > >  drivers/gpu/drm/i915/intel_drv.h    |  2 ++
> > >  drivers/gpu/drm/i915/intel_hdmi.c   | 11 +++++++++++
> > >  drivers/gpu/drm/i915/intel_modes.c  | 20 ++++++++++++++++++++
> > 
> > Pls move all the i915 stuff to the second patch.
> Sure will do it in the next rev.
> 
> > 
> > >  include/drm/drm_connector.h         |  6 ++++++
> > >  include/drm/drm_mode_config.h       |  5 +++++
> > >  7 files changed, 52 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> > > index 3eb061e11e2e..461dde0c2c10 100644
> > > --- a/drivers/gpu/drm/drm_atomic.c
> > > +++ b/drivers/gpu/drm/drm_atomic.c
> > > @@ -1416,6 +1416,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
> > >  
> > >  		return set_out_fence_for_connector(state->state, connector,
> > >  						   fence_ptr);
> > > +	} else if (property == config->max_bpc_property) {
> > > +		state->max_bpc = val;
> > >  	} else if (connector->funcs->atomic_set_property) {
> > >  		return connector->funcs->atomic_set_property(connector,
> > >  				state, property, val);
> > > @@ -1511,6 +1513,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
> > >  		*val = 0;
> > >  	} else if (property == config->writeback_out_fence_ptr_property) {
> > >  		*val = 0;
> > > +	} else if (property == config->max_bpc_property) {
> > > +		*val = state->max_bpc;
> > >  	} else if (connector->funcs->atomic_get_property) {
> > >  		return connector->funcs->atomic_get_property(connector,
> > >  				state, property, val);
> > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> > > index 38ce9a375ffb..82caac8d1432 100644
> > > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > > @@ -638,6 +638,10 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
> > >  			if (old_connector_state->link_status !=
> > >  			    new_connector_state->link_status)
> > >  				new_crtc_state->connectors_changed = true;
> > > +
> > > +			if (old_connector_state->max_bpc !=
> > > +			    new_connector_state->max_bpc)
> > > +				new_crtc_state->connectors_changed = true;
> > >  		}
> > >  
> > >  		if (funcs->atomic_check)
> > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > > index 1b78de838c18..209eb1798238 100644
> > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > @@ -1862,6 +1862,8 @@ int intel_ddc_get_modes(struct drm_connector *c, struct i2c_adapter *adapter);
> > >  void intel_attach_force_audio_property(struct drm_connector *connector);
> > >  void intel_attach_broadcast_rgb_property(struct drm_connector *connector);
> > >  void intel_attach_aspect_ratio_property(struct drm_connector *connector);
> > > +void intel_attach_max_bpc_property(struct drm_connector *connector, int min, int
> > > +				   max);
> > >  
> > >  
> > >  /* intel_overlay.c */
> > > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> > > index a1799b5c12bb..82739f342246 100644
> > > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > > @@ -2097,11 +2097,22 @@ 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 (IS_G4X(dev_priv) || IS_VALLEYVIEW(dev_priv) ||
> > > +	    IS_CHERRYVIEW(dev_priv)) {
> > > +		intel_attach_max_bpc_property(connector, 8, 10);
> > > +		connector->state->max_bpc = 10;
> > 
> > These platforms don't support HDMI deep color. The 10bpc stuff in
> > PIPECONF is for DP. Incidentally DP support seems to be missing from
> > this series.
> Limiting this to 8 and removing VLV/CHV to the other case as they support deep color.

They don't.

> 
> > 
> > > +	} else if (INTEL_GEN(dev_priv) >= 5) {

if (!HAS_GMCH_DISPLAY()) {
 ...

should be what we want here.


> > > +		intel_attach_max_bpc_property(connector, 8, 12);
> > > +		connector->state->max_bpc = 12;
> > > +	}
> > >  }
> > >  
> > >  /*
> > > diff --git a/drivers/gpu/drm/i915/intel_modes.c b/drivers/gpu/drm/i915/intel_modes.c
> > > index ca44bf368e24..78f2ce92f194 100644
> > > --- a/drivers/gpu/drm/i915/intel_modes.c
> > > +++ b/drivers/gpu/drm/i915/intel_modes.c
> > > @@ -133,3 +133,23 @@ intel_attach_aspect_ratio_property(struct drm_connector *connector)
> > >  			connector->dev->mode_config.aspect_ratio_property,
> > >  			DRM_MODE_PICTURE_ASPECT_NONE);
> > >  }
> > > +
> > > +void
> > > +intel_attach_max_bpc_property(struct drm_connector *connector, int min, int
> > > +			       max)
> > > +{
> > > +	struct drm_device *dev = connector->dev;
> > > +	struct drm_mode_config *config = &dev->mode_config;
> > > +	struct drm_property *prop;
> > > +
> > > +	prop = config->max_bpc_property;
> > > +	if (prop == NULL) {
> > > +		prop = drm_property_create_range(dev, 0, "max bpc", min, max);
> > > +		if (prop == NULL)
> > > +			return;
> > > +
> > > +		config->max_bpc_property = prop;
> > > +	}
> > > +
> > > +	drm_object_attach_property(&connector->base, prop, max);
> > 
> > Might make sense to do 'connector->state->max_bpc = max' here.
> > Avoids having to sprinkle it in every driver.
> Sure will make this change in the next rev.
> 
> > 
> > > +}
> > > diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> > > index 97ea41dc678f..d59b9e34ae80 100644
> > > --- a/include/drm/drm_connector.h
> > > +++ b/include/drm/drm_connector.h
> > > @@ -460,6 +460,12 @@ struct drm_connector_state {
> > >  	 * drm_writeback_signal_completion()
> > >  	 */
> > >  	struct drm_writeback_job *writeback_job;
> > > +
> > > +	/**
> > > +	 * @max_bpc: Connector property to limit the maximum bit depth of
> > > +	 * the pixels being scanned out.
> > 
> > The comment is misleading. It makes me think this has something to do
> > with the pixels we scan out from a framebuffer.
> Will modify this comment in the next rev.
> 
> Regards,
> Radhakrishna(RK) Sripada
> > 
> > > +	 */
> > > +	unsigned int max_bpc;
> > >  };
> > >  
> > >  /**
> > > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> > > index a0b202e1d69a..b9cd7a73b244 100644
> > > --- a/include/drm/drm_mode_config.h
> > > +++ b/include/drm/drm_mode_config.h
> > > @@ -562,6 +562,11 @@ struct drm_mode_config {
> > >  	 */
> > >  	struct drm_property *link_status_property;
> > >  	/**
> > > +	 * @max_bpc_property: Default connector property for the max bpc to be
> > > +	 * driven out of the connector.
> > > +	 */
> > > +	struct drm_property *max_bpc_property;
> > > +	/**
> > >  	 * @plane_type_property: Default plane property to differentiate
> > >  	 * CURSOR, PRIMARY and OVERLAY legacy uses of planes.
> > >  	 */
> > > -- 
> > > 2.9.3
> > 
> > -- 
> > Ville Syrjälä
> > Intel

-- 
Ville Syrjälä
Intel


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