On Mon, Jul 13, 2026 at 01:23:00PM +0300, Cristian Ciocaltea wrote:
> On 7/13/26 11:50 AM, Maxime Ripard wrote:
> > On Thu, Jul 09, 2026 at 10:25:54PM +0300, Cristian Ciocaltea wrote:
> >> On 7/3/26 11:54 PM, Cristian Ciocaltea wrote:
> >>> On 7/3/26 5:34 PM, Dmitry Baryshkov wrote:
> >>>> On Thu, Jul 02, 2026 at 05:46:17PM +0300, Cristian Ciocaltea wrote:
> >>>>> Add the connector-level infrastructure to support HDMI 2.0 scrambling:
> >>>>>
> >>>>> - A scrambler_supported flag to indicate whether the source supports the
> >>>>> scrambling capability, in which case the newly introduced
> >>>>> .scrambler_{enable|disable}() callbacks in drm_connector_hdmi_funcs
> >>>>> are mandatory
> >>>>
> >>>> Do we need a flag? What would it mean if the flag is set, but the
> >>>> callbacks are not? Can we drop the flag and use the presence of the
> >>>> callbacks as a way to identify that scrambler is enabled?
> >>>
> >>> The flag is intended to be set only within
> >>> drmm_connector_hdmi_init_with_caps()
> >>> when drivers advertise HDMI 2.x capability, in which case it also ensures
> >>> the
> >>> callbacks are provided.
> >>>
> >>> We could drop the flag and instead have the init helper clear the
> >>> callbacks if
> >>> they were provided for HDMI 1.x. This might slightly reduce code
> >>> readability,
> >>> as it relies on checking the presence of individual callbacks -
> >>> especially since
> >>> we plan to extend this further with HDMI 2.1 support, providing four or
> >>> five
> >>> additional FRL-specific callbacks.
> >>
> >> I tried to replace the flag with a helper that checks the presence of (one
> >> of)
> >> the callbacks, but it's not straightforward to unset those for non-HDMI 2.x
> >> cases since the hdmi_funcs argument is immutable.
> >
> > I'm not sure why we would need to unset them. If the driver states that
> > it support HDMI 2.0, then it needs to be there, if it doesn't, then who
> > cares? it's not going to be used. We can log a warning that it's
> > inconsistent I guess, but there's no need to actively remove it.
>
> I was trying to address the use case where drivers provide the scrambler
> callbacks despite not supporting HDMI 2.0.
Scrambling got introduced with HDMI 2.0. That doesn't make sense, but
it's not a total deal breaker, it's just going to be here unused. Hence
why I was suggesting to put a warning there if you wanted to.
> If we replace the scrambler_supported flag with a helper checking the
> presence of the scrambler callbacks, then we would need to ensure the
> callbacks do not exist in this case.
Keep it simple:
if (hdmi_version >= HDMI_VERSION_2_0)
if (funcs->scrambler_enable)
hdmi->scramblers_supported = true
else
return -EINVAL
else
drm_warn(warn, "Inconsistent HDMI version");
We don't need anything more than that.
Maxime
signature.asc
Description: PGP signature
