On Tue, Feb 13, 2024 at 11:26:44AM +0200, Ville Syrjälä wrote: > On Mon, Feb 12, 2024 at 05:50:36PM +0100, Sebastian Wick wrote: > > On Mon, Feb 12, 2024 at 11:10:15AM +0200, Pekka Paalanen wrote: > > > On Fri, 9 Feb 2024 17:53:07 +0100 > > > Xaver Hugl <xaver.hugl@xxxxxxx> wrote: > > > > > > > Signed-off-by: Xaver Hugl <xaver.hugl@xxxxxxx> > > > > --- > > > > drivers/gpu/drm/drm_connector.c | 8 ++++++++ > > > > 1 file changed, 8 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c > > > > index b0516505f7ae..01e13984629b 100644 > > > > --- a/drivers/gpu/drm/drm_connector.c > > > > +++ b/drivers/gpu/drm/drm_connector.c > > > > @@ -2158,6 +2158,14 @@ EXPORT_SYMBOL(drm_mode_create_aspect_ratio_property); > > > > * one supported. Sink supported colorspaces should be retrieved by > > > > * userspace from EDID and driver will not explicitly expose them. > > > > * > > > > + * As userspace can't currently know whether or not the output is using > > > > + * RGB or YCC signalling, the driver must translate properties to their > > > > + * relevant RGB or YCC counterparts, depending on the actually used > > > > + * signalling. Property values that are only valid for either YCC or RGB > > > > + * and have no equivalent for the other signalling type must not be > > > > + * exposed as supported, unless the driver can guarantee it never uses > > > > + * the signalling that doesn't match the property. > > > > + * > > > > * Basically the expectation from userspace is: > > > > * - Set up CRTC DEGAMMA/CTM/GAMMA to convert to some sink > > > > * colorspace > > > > > > While this addition is good, I have another question: > > > > > > Does "Colorspace" property choose also the RGB->YCbCr matrix that the > > > driver will use when it happens to use YCbCr signalling? > > > > > > So far we have only been talking about the primaries and white point. > > > > Uh, yeah, good point. The InfoFrames do affect both the YCbCr conversion > > and the transfer characteristics that the sink expects. Drivers should > > do the RGB to YCbCr conversion with the new matrix. I think (and very > > much hope) that drivers don't rely on the TF for any internal processing > > but if they did, they also should use the one the sink expects. > > What we need is: > - list of the property values that are still allowd (the ones that still > make sense with the changed semantics) > - mark all the other ones as deprecated > - filter/reject the deprecated values when creating the property > - document each valid enum value fully (for both RGB and YCbCr output): > * what exacly is signalled to the sink via infoframe/msa/vsc sdp > * what processing is the driver expected to perform on the actual data I'm starting to agree that this is a better idea than coming up with a number of rules. We only rely on the default colorimetry as indicated by EDID and BT.2020. Xaver, are you going to update the patch accordingly? > -- > Ville Syrjälä > Intel >
