[Intel-gfx] [PATCH] Add support for Color encoding YCBCR_BT2020

[Shankar, Uma]

> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Sent: Friday, February 14, 2020 8:03 PM
> To: Shankar, Uma <uma.shankar at intel.com>
> Cc: Kadiyala, Kishore <kishore.kadiyala at intel.com>; intel-gfx at lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH] Add support for Color encoding YCBCR_BT2020
> 
> On Fri, Feb 14, 2020 at 02:27:35PM +0000, Shankar, Uma wrote:
> >
> >
> > > -----Original Message-----
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Sent: Friday, February 14, 2020 6:40 PM
> > > To: Kadiyala, Kishore <kishore.kadiyala at intel.com>
> > > Cc: intel-gfx at lists.freedesktop.org; Shankar, Uma
> > > <uma.shankar at intel.com>
> > > Subject: Re: [Intel-gfx] [PATCH] Add support for Color encoding
> > > YCBCR_BT2020
> > >
> > > On Fri, Feb 14, 2020 at 04:23:16PM +0530, Kishore Kadiyala wrote:
> > > > Currently the plane property doesn't have support for
> > > > YCBCR_BT2020, which enables the corresponding color conversion mode on
> plane CSC.
> > > >
> > > > Signed-off-by: Kishore Kadiyala <kishore.kadiyala at intel.com>
> > > > Cc: Uma Shankar <uma.shankar at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_sprite.c | 9 +++++++--
> > > >  1 file changed, 7 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c
> > > > b/drivers/gpu/drm/i915/display/intel_sprite.c
> > > > index 7abeefe8dce5..5169a7260d7c 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> > > > @@ -3011,6 +3011,7 @@ skl_universal_plane_create(struct
> > > > drm_i915_private
> > > *dev_priv,
> > > >  	struct intel_plane *plane;
> > > >  	enum drm_plane_type plane_type;
> > > >  	unsigned int supported_rotations;
> > > > +	unsigned int supported_csc;
> > > >  	unsigned int possible_crtcs;
> > > >  	const u64 *modifiers;
> > > >  	const u32 *formats;
> > > > @@ -3088,9 +3089,13 @@ skl_universal_plane_create(struct
> > > > drm_i915_private
> > > *dev_priv,
> > > >  					   DRM_MODE_ROTATE_0,
> > > >  					   supported_rotations);
> > > >
> > > > +	supported_csc = BIT(DRM_COLOR_YCBCR_BT601) |
> > > > +BIT(DRM_COLOR_YCBCR_BT709);
> > > > +
> > > > +	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
> > > > +		supported_csc |= BIT(DRM_COLOR_YCBCR_BT2020);
> > >
> > > Missing the actual code to enable it on glk and icl+ sdr planes, so this will not
> work.
> >
> > Yeah this need to be handled for Non HDR planes.
> >
> > > IIRC there was also some kind of hw fail related to some BT.something
> conversions.
> > > But I can't remember if that was in the RGB->RGB or
> > > YUV->RGB logic.
> >
> > Will try to check this out. What kind of fails Ville, was it not all working or artifacts
> ?
> 
> IIRC a wrong coefficient was used in one of the hardcoded hw matrices. Should be
> listed on the bspec w/a page.

Able to retrieve that, looks like it's for RGB709 to RGB2020 conversion on SDR planes.
So recommendation is not to enable this conversion for SDR planes.

Thanks Ville.

Regards,
Uma Shankar

> --
> Ville Syrjälä
> Intel