[PATCH v6] unstable/drm-lease: DRM lease protocol support

[Drew DeVault]

On Mon Sep 2, 2019 at 3:51 PM Pekka Paalanen wrote:
> Hi Drew,
> 
> I seem to recall that you didn't want to add multi-DRM-device support
> here just yet and go first with just one implied DRM device. That is
> ok, but would be nice to have a TODO note somewhere near the top in the
> XML file saying that this will be re-designed to support multiple DRM
> devices at some point.

This was resolved by choosing to have multiple drm_lease_manager
globals, one for each DRM device. No reworking should be necessary.

> Can you point to the discussion or elaborate here on when a zero
> connector lease would be useful?
> 
> I checked the Xwayland discussion and didn't see it there. I remember
> some old talk about giving out a no-resources lease first for
> discovering DRM resources to lease, but that didn't work because
> non-leased resources would not be visible either.

https://gitlab.freedesktop.org/xorg/xserver/issues/864

The main issue is that we have no way to enumerate detailed mode
information in Xwayland to populate RandR, which is used by X clients in
the wild today to prep for a DRM lease (the corresponding X extension
for Vulkan is an example of where this is a problem).