On Mon, Apr 3, 2017 at 12:56 PM, Keith Packard <keithp@keithp.com> wrote:

> Chad Versace <chadversary@chromium.org> writes:
>
> > The real path forward should be implemented on top of
> > VK_KHX_external_memory. If you want to start experimenting now with
> > Vulkan+KMS, you may want to look at
> > VK_EXTERNAL_MEMORY_HANDLE_OPAQUE_FD_KHX.
>
> It seems like the Vulkan spec for WSI with devices has a bunch of what I
> would need to implement in a standard fashion; I guess I'm unclear
> whether I should go down the route of wrapping all of DRM/KMS in a WSI
> layer, or use some of this lower-level stuff directly from the
> application instead?
>

Interesting question.  To my knowledge, no one has actually implemented the
Vulkan WSI direct-to-display extensions.  (I tried to prevent them from
getting released with 1.0 but failed.)  I believe the correct answer is to
use the external memory dma-buf stuff that chad and I have been using and
talk directly to KMS.  I see no good reason to have a large abstraction in
the middle.  dma-buf + KMS should give you Intel and radeon (with radv) so
that's most of it.  In particular, it will give you 100% of people who
actually care about DRM leases. :-)