[Mesa-stable] Wayland format fixes for stable branches

[Mario Kleiner]

On Wed, Jan 30, 2019 at 6:45 PM Emil Velikov <emil.l.velikov at gmail.com> wrote:
>
> Hi all,
>
> AFAICT the following two patches are a must have if we're interested
> in properly working PRIME with the new color depth 30 formats.
> Mario, others what do you thing?
>

You certainly have my blessing. They are needed at least if the client
gpu is NVidia/nouveau and the server gpu is Intel or AMD, e.g., your
classic "Optimus" laptop. At least when the wl_drm protocol is used.
My memory is a bit faint from 8 months ago, but iirc at least Weston's
experimental wayland dmabuf protocol support of that time could still
accept depth 30 formats, as it uses a different type of signalling of
supported formats. However, zero-copy presents via direct pageflipping
didn't work then, so there was a large impact on performance.

These were originally developed and tested last may against Mesa 18.1
or 18.2, so applying them to current stable should work without
problems.

I also have this quite old weston branch, with patches to allow
zero-copy presents of depth 30 in weston and for supporting NVidia's
depth 30 format. I used this for testing at that time, but didn't
clean them up for upstream without the Mesa bits in place. I will see
if i can dust them off...

https://github.com/kleinerm/weston/commits/westonnew10bpc

I also remember having to hack-disable weston's dmabuf protocol
support so it would fall back to the older wl_drm protocol in order to
allow testing of these mesa patches.

-mario

> Thanks
> Emil
>
> a34b0d68bbf egl/wayland: Allow client->server format conversion for
> PRIME offload. (v2)
> 820dfcea431 egl/wayland-drm: Only announce formats via wl_drm which
> the driver supports.