[PATCH wayland-protocols v7] Add zwp_linux_explicit_synchronization_v1

[Alexandros Frantzis]

On Fri, Nov 09, 2018 at 04:24:56PM +0200, Alexandros Frantzis wrote:
> On Fri, Nov 09, 2018 at 12:48:09PM +0200, Pekka Paalanen wrote:
> > On Fri,  9 Nov 2018 09:46:36 +0200
> > Alexandros Frantzis <alexandros.frantzis at collabora.com> wrote:
> > 
> > > Signed-off-by: Alexandros Frantzis <alexandros.frantzis at collabora.com>
> > 
> > Hi Alf,
> 
> Hi Pekka,
> 
> thanks for the review!
> 
> > could you come up with some rationale to put in the commit message on
> > why this extension is being added?
> > 
> > I can add that while pushing upstream, if there are no other changes
> > coming.
> 
> How about:
> 
> This protocol enables explicit synchronization of asynchronous graphics
> operations on buffers on a per-commit basis. Support is currently
> limited to dmabuf buffers and dma_fence fence FDs.
> 
> Explicit synchronization provides a more versatile notification
> mechanism for buffer readiness and availability, and can be used to
> improve efficiency by integrating with related functionality in display
> and graphics APIs.
> 
> Finally, the per-commit nature of the release events provided by this
> protocol offer a solution to a deficiency of the wl_buffer.release event
> (see https://gitlab.freedesktop.org/wayland/wayland/issues/46).

v2 of the text, with some more ChromeOS related information:

This protocol enables explicit synchronization of asynchronous graphics
operations on buffers on a per-commit basis. Support is currently
limited to dmabuf buffers and dma_fence fence FDs.

Explicit synchronization provides a more versatile notification
mechanism for buffer readiness and availability, and can be used to
improve efficiency by integrating with related functionality in display
and graphics APIs.

This protocol is also useful in ChromeOS ARC++ (running Android apps
inside ChromeOS, using Wayland as the communication protocol), where it
can enable integration of the ChromeOS compositor with the explicit
synchronization mechanisms of the Android display subsystem.

Finally, the per-commit nature of the release events provided by this
protocol potentially offers a solution to a deficiency of the
wl_buffer.release event (see
https://gitlab.freedesktop.org/wayland/wayland/issues/46).

Thanks,
Alexandros