[PATCH] drm/fourcc: Document open source user waiver

[Bas Nieuwenhuizen]

Acked-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>

On Thu, Dec 1, 2022 at 8:47 PM Jason Ekstrand <jason at jlekstrand.net> wrote:
>
> Acked-by: Jason Ekstrand <jason.ekstrand at collabora.com>
>
> On Thu, Dec 1, 2022 at 4:22 AM Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
>>
>> On Thu, 1 Dec 2022 at 11:07, Daniel Vetter <daniel at ffwll.ch> wrote:
>> >
>> > On Wed, Nov 23, 2022 at 08:24:37PM +0100, Daniel Vetter wrote:
>> > > It's a bit a FAQ, and we really can't claim to be the authoritative
>> > > source for allocating these numbers used in many standard extensions
>> > > if we tell closed source or vendor stacks in general to go away.
>> > >
>> > > Iirc this was already clarified in some vulkan discussions, but I
>> > > can't find that anywhere anymore. At least not in a public link.
>> > >
>> > > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> > > Cc: Maxime Ripard <mripard at kernel.org>
>> > > Cc: Thomas Zimmermann <tzimmermann at suse.de>
>> > > Cc: David Airlie <airlied at gmail.com>
>> > > Cc: Daniel Vetter <daniel at ffwll.ch>
>> > > Cc: Alex Deucher <alexdeucher at gmail.com>
>> > > Cc: Daniel Stone <daniel at fooishbar.org>
>> > > Cc: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
>> > > Cc: Jason Ekstrand <jason at jlekstrand.net>
>> > > Cc: Neil Trevett <ntrevett at nvidia.com>
>> > > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>> >
>> > From irc:
>> >
>> > <airlied> danvet: ack from me
>>
>> Also from irc:
>>
>> <mareko> danvet: Acked
>>
>> -Daniel
>>
>> > > ---
>> > >  include/uapi/drm/drm_fourcc.h | 12 ++++++++++++
>> > >  1 file changed, 12 insertions(+)
>> > >
>> > > diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
>> > > index bc056f2d537d..de703c6be969 100644
>> > > --- a/include/uapi/drm/drm_fourcc.h
>> > > +++ b/include/uapi/drm/drm_fourcc.h
>> > > @@ -88,6 +88,18 @@ extern "C" {
>> > >   *
>> > >   * The authoritative list of format modifier codes is found in
>> > >   * `include/uapi/drm/drm_fourcc.h`
>> > > + *
>> > > + * Open Source User Waiver
>> > > + * -----------------------
>> > > + *
>> > > + * Because this is the authoritative source for pixel formats and modifiers
>> > > + * referenced by GL, Vulkan extensions and other standards and hence used both
>> > > + * by open source and closed source driver stacks, the usual requirement for an
>> > > + * upstream in-kernel or open source userspace user does not apply.
>> > > + *
>> > > + * To ensure, as much as feasible, compatibility across stacks and avoid
>> > > + * confusion with incompatible enumerations stakeholders for all relevant driver
>> > > + * stacks should approve additions.
>> > >   */
>> > >
>> > >  #define fourcc_code(a, b, c, d) ((__u32)(a) | ((__u32)(b) << 8) | \
>> > > --
>> > > 2.37.2
>> > >
>> >
>> > --
>> > Daniel Vetter
>> > Software Engineer, Intel Corporation
>> > http://blog.ffwll.ch
>>
>>
>>
>> --
>> Daniel Vetter
>> Software Engineer, Intel Corporation
>> http://blog.ffwll.ch