[Intel-gfx] [RFC v4 3/8] drm: Add Plane CTM property

Lankhorst, Maarten maarten.lankhorst at intel.com
Wed Aug 22 12:51:47 UTC 2018


ons 2018-08-22 klockan 12:11 +0100 skrev Brian Starkey:
> Hi,
> 
> On Wed, Aug 22, 2018 at 12:53:58PM +0300, Ville Syrjälä wrote:
> > On Wed, Aug 22, 2018 at 08:40:19AM +0000, Lankhorst, Maarten wrote:
> > > fre 2018-08-17 klockan 19:48 +0530 skrev Uma Shankar:
> > > > Add a blob property for plane CSC usage.
> > > > 
> > > > v2: Rebase
> > > > 
> > > > v3: Fixed Sean, Paul's review comments. Moved the property from
> > > > mode_config to drm_plane. Created a helper function to
> > > > instantiate
> > > > these properties and removed from
> > > > drm_mode_create_standard_properties
> > > > Added property documentation as suggested by Daniel, Vetter.
> > > > 
> > > > v4: Rebase
> > > > 
> > > > Signed-off-by: Uma Shankar <uma.shankar at intel.com>
> > > > ---
> > > >  Documentation/gpu/drm-kms.rst       |  3 +++
> > > >  drivers/gpu/drm/drm_atomic.c        | 10 ++++++++++
> > > >  drivers/gpu/drm/drm_atomic_helper.c |  4 ++++
> > > >  drivers/gpu/drm/drm_plane.c         | 12 ++++++++++++
> > > >  include/drm/drm_plane.h             | 15 +++++++++++++++
> > > >  5 files changed, 44 insertions(+)
> > > > 
> > > > diff --git a/Documentation/gpu/drm-kms.rst
> > > > b/Documentation/gpu/drm-
> > > > kms.rst
> > > > index 8b10b12..16d6d8d 100644
> > > > --- a/Documentation/gpu/drm-kms.rst
> > > > +++ b/Documentation/gpu/drm-kms.rst
> > > > @@ -560,6 +560,9 @@ Plane Color Management Properties
> > > >  .. kernel-doc:: drivers/gpu/drm/drm_plane.c
> > > >     :doc: degamma_lut_size_property
> > > > 
> > > > +.. kernel-doc:: drivers/gpu/drm/drm_plane.c
> > > > +   :doc: ctm_property
> > > > +
> > > >  Tile Group Property
> > > >  -------------------
> > > > 
> > > > diff --git a/drivers/gpu/drm/drm_atomic.c
> > > > b/drivers/gpu/drm/drm_atomic.c
> > > > index f8cad9b..ddda935 100644
> > > > --- a/drivers/gpu/drm/drm_atomic.c
> > > > +++ b/drivers/gpu/drm/drm_atomic.c
> > > > @@ -917,6 +917,14 @@ static int
> > > > drm_atomic_plane_set_property(struct
> > > > drm_plane *plane,
> > > >  					&replaced);
> > > >  		state->color_mgmt_changed |= replaced;
> > > >  		return ret;
> > > > +	} else if (property == plane->ctm_property) {
> > > > +		ret =
> > > > drm_atomic_replace_property_blob_from_id(dev,
> > > > +					&state->ctm,
> > > > +					val,
> > > > +					sizeof(struct
> > > > drm_color_ctm), -1,
> > > > +					&replaced);
> > > > +		state->color_mgmt_changed |= replaced;
> > > > +		return ret;
> > > >  	} else if (plane->funcs->atomic_set_property) {
> > > >  		return plane->funcs-
> > > > >atomic_set_property(plane,
> > > > state,
> > > >  				property, val);
> > > > @@ -988,6 +996,8 @@ static int
> > > > drm_atomic_plane_set_property(struct
> > > > drm_plane *plane,
> > > >  	} else if (property == plane->degamma_lut_property) {
> > > >  		*val = (state->degamma_lut) ?
> > > >  			state->degamma_lut->base.id : 0;
> > > > +	} else if (property == plane->ctm_property) {
> > > > +		*val = (state->ctm) ? state->ctm->base.id : 0;
> > > >  	} else if (plane->funcs->atomic_get_property) {
> > > >  		return plane->funcs-
> > > > >atomic_get_property(plane,
> > > > state, property, val);
> > > >  	} else {
> > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c
> > > > b/drivers/gpu/drm/drm_atomic_helper.c
> > > > index 67c5b51..866181f 100644
> > > > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > > > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > > > @@ -3616,6 +3616,9 @@ void
> > > > __drm_atomic_helper_plane_duplicate_state(struct drm_plane
> > > > *plane,
> > > > 
> > > >  	if (state->degamma_lut)
> > > >  		drm_property_blob_get(state->degamma_lut);
> > > > +	if (state->ctm)
> > > > +		drm_property_blob_get(state->ctm);
> > > > +
> > > >  	state->color_mgmt_changed = false;
> > > >  }
> > > >  EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
> > > > @@ -3663,6 +3666,7 @@ void
> > > > __drm_atomic_helper_plane_destroy_state(struct drm_plane_state
> > > > *state)
> > > >  		drm_crtc_commit_put(state->commit);
> > > > 
> > > >  	drm_property_blob_put(state->degamma_lut);
> > > > +	drm_property_blob_put(state->ctm);
> > > >  }
> > > >  EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
> > > > 
> > > > diff --git a/drivers/gpu/drm/drm_plane.c
> > > > b/drivers/gpu/drm/drm_plane.c
> > > > index 03e0560..97520b1 100644
> > > > --- a/drivers/gpu/drm/drm_plane.c
> > > > +++ b/drivers/gpu/drm/drm_plane.c
> > > > @@ -489,6 +489,11 @@ int drm_mode_plane_set_obj_prop(struct
> > > > drm_plane
> > > > *plane,
> > > >   *
> > > >   * degamma_lut_size_property:
> > > >   *	Range Property to indicate size of the plane degamma
> > > > LUT.
> > > > + *
> > > > + * ctm_property:
> > > > + *	Blob property which allows a userspace to provide
> > > > CTM
> > > > coefficients
> > > > + *	to do color space conversion or any other
> > > > enhancement by
> > > > doing a
> > > > + *	matrix multiplication using the h/w CTM processing
> > > > engine
> > > >   */
> > > >  int drm_plane_color_create_prop(struct drm_device *dev,
> > > >  				struct drm_plane *plane)
> > > > @@ -509,6 +514,13 @@ int drm_plane_color_create_prop(struct
> > > > drm_device *dev,
> > > >  		return -ENOMEM;
> > > >  	plane->degamma_lut_size_property = prop;
> > > > 
> > > > +	prop = drm_property_create(dev,
> > > > +			DRM_MODE_PROP_BLOB,
> > > > +			"PLANE_CTM", 0);
> > > > +	if (!prop)
> > > > +		return -ENOMEM;
> > > > +	plane->ctm_property = prop;
> > > > +
> > > >  	return 0;
> > > >  }
> > > >  EXPORT_SYMBOL(drm_plane_color_create_prop);
> > > > diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> > > > index 28357ac..5143277 100644
> > > > --- a/include/drm/drm_plane.h
> > > > +++ b/include/drm/drm_plane.h
> > > > @@ -183,6 +183,14 @@ struct drm_plane_state {
> > > >  	struct drm_property_blob *degamma_lut;
> > > > 
> > > >  	/**
> > > > +	 * @ctm:
> > > > +	 *
> > > > +	 * Color transformation matrix. See
> > > > drm_plane_enable_color_mgmt(). The
> > > > +	 * blob (if not NULL) is a &struct drm_color_ctm.
> > > > +	 */
> > > > +	struct drm_property_blob *ctm;
> > > > +
> > > > +	/**
> > > >  	 * @commit: Tracks the pending commit to prevent use-
> > > > after-
> > > > free conditions,
> > > >  	 * and for async plane updates.
> > > >  	 *
> > > > @@ -698,6 +706,13 @@ struct drm_plane {
> > > >  	 * size of the degamma LUT as supported by the driver
> > > > (read-
> > > > only).
> > > >  	 */
> > > >  	struct drm_property *degamma_lut_size_property;
> > > > +
> > > > +	/**
> > > > +	 * @plane_ctm_property: Optional Plane property to set
> > > > the
> > > > +	 * matrix used to convert colors after the lookup in
> > > > the
> > > > +	 * degamma LUT.
> > > > +	 */
> > > > +	struct drm_property *ctm_property;
> > > > 
> > > 
> > > I'm assuming degamma is done before converting with CTM.
> > > 
> > > But how does this interact with YUV formats? I'm not sure this is
> > > explicitly defined. I'm assuming R->Cr G -> Y, B = Cb for degamma
> > > tables.
> > 
> > The pipeline is (or at least should be IMO):
> > ycbcr->rgb -> degamma -> ctm -> gamma
> > 
> 
> That's what I'm expecting too.
> 
> > We should document the full pipeline (including the crtc portions)
> > in
> > some docs.
> 
> I fully agree with Ville here, we've been around this loop a few
> times, so the full pipeline and expectations need to be captured
> in docs (IMO before the properties can be decided).
> 
> It's slightly unfortunate that the merged ycbcr->rgb properties only
> describe the format of the incoming buffer, without any specification
> of what the driver is meant to do with that information (what
> conversion is meant to be performed?). Without that, this new CTM
> property is somewhat useless, because generic userspace can't tell
> what the input data to the matrix is in YUV cases - so we need to
> decide and document that too (or change/enhance the API).
As long as it's documented I'm fine with it. :-)
Also curious on how it interacts with CRTC pipeline.

~Maarten
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