Re: [PATCH v7 21/36] drm/connector: hdmi: Add Broadcast RGB property

Maxime Ripard
2024-03-01T10:31:21Z

On Thu, Feb 29, 2024 at 08:47:26PM +0100, Sebastian Wick wrote:
> > @@ -1708,6 +1731,39 @@ EXPORT_SYMBOL(drm_connector_attach_dp_subconnector_property);
> > /**
> > * DOC: HDMI connector properties
> > *
> > + * Broadcast RGB (HDMI specific)
> > + * Indicates the Quantization Range (Full vs Limited) used. The color
> > + * processing pipeline will be adjusted to match the value of the
> > + * property, and the Infoframes will be generated and sent accordingly.
> > + *
> > + * This property is only relevant if the HDMI output format is RGB. If
> > + * it's one of the YCbCr variant, it will be ignored and the output will
> > + * use a limited quantization range.
>
> Uh, maybe just say that the quantization range is selected automatically
> in case a YCbCr output format is in use. I'm not sure every YCbCr
> variant requires limited and even if it does, new formats could change
> this.

I documented what i915 is doing:
https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/i915/display/intel_hdmi.c#L2143

Maxime