Re: [RFC] Plane color pipeline KMS uAPI

[Karol Herbst <kherbst@redhat.com>]

On Wed, May 10, 2023 at 9:59 AM Jonas Ådahl <jadahl@redhat.com> wrote:
>
> On Tue, May 09, 2023 at 08:22:30PM +0000, Simon Ser wrote:
> > On Tuesday, May 9th, 2023 at 21:53, Dave Airlie <airlied@gmail.com> wrote:
> >
> > > There are also other vendor side effects to having this in userspace.
> > >
> > > Will the library have a loader?
> > > Will it allow proprietary plugins?
> > > Will it allow proprietary reimplementations?
> > > What will happen when a vendor wants distros to ship their
> > > proprietary fork of said library?
> > >
> > > How would NVIDIA integrate this with their proprietary stack?
> >
> > Since all color operations exposed by KMS are standard, the library
> > would just be a simple one: no loader, no plugin, no proprietary pieces,
> > etc.
> >
>
> There might be pipelines/color-ops only exposed by proprietary out of
> tree drivers; the operation types and semantics should ideally be
> defined upstream, but the code paths would in practice be vendor
> specific, potentially without any upstream driver using them. It should
> be clear whether an implementation that makes such a pipeline work is in
> scope for the upstream library.
>
> The same applies to the kernel; it must be clear whether pipeline
> elements that potentially will only be exposed by out of tree drivers
> will be acceptable upstream, at least as documented operations.
>

they aren't. All code in the kernel needs to be used by in-tree
drivers otherwise it's fair to delete it. DRM requires any UAPI change
to have a real open source user in space user.

Nvidia knows this and they went to great lengths to fulfill this
requirement in the past. They'll manage.

>
> Jonas
>