Re: [RFC] Plane color pipeline KMS uAPI

From: Pekka Paalanen <ppaalanen@gmail.com>
To: "Jonas Ådahl" <jadahl@redhat.com>
Cc: "Sebastian Wick" <sebastian.wick@redhat.com>,
	"Aleix Pol" <aleixpol@kde.org>,
	"DRI Development" <dri-devel@lists.freedesktop.org>,
	"xaver.hugl@gmail.com" <xaver.hugl@gmail.com>,
	"Melissa Wen" <mwen@igalia.com>,
	"Michel Dänzer" <mdaenzer@redhat.com>,
	"Uma Shankar" <uma.shankar@intel.com>,
	"Victoria Brekenfeld" <victoria@system76.com>,
	wayland-devel <wayland-devel@lists.freedesktop.org>,
	"Joshua Ashton" <joshua@froggi.es>
Subject: Re: [RFC] Plane color pipeline KMS uAPI
Date: Wed, 10 May 2023 11:59:28 +0300	[thread overview]
Message-ID: <20230510115928.42755c9d@eldfell> (raw)
In-Reply-To: <ZFtO2bMQOWVhRkSG@redhat.com>

[-- Attachment #1: Type: text/plain, Size: 1889 bytes --]

On Wed, 10 May 2023 09:59:21 +0200
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.

In my opinion, a COLOROP element definition can be accepted in the
upstream kernel documentation only if there is also an upstream driver
implementing it. It does not need to be a "direct" hardware
implementation, it could also be the upstream driver mapping the
COLOROP to whatever hardware block or block chain it has.

For the userspace library I don't know. I am puzzled whether people
want to allow proprietary components or deny them.

Thanks,
pq

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]