[Intel-gfx] [RFC v2] drm/i915: Android native sync support

[Chris Wilson]

On Mon, Jan 26, 2015 at 08:52:39AM +0100, Daniel Vetter wrote:
> I think the problem will be platforms that want full explicit fence (like
> android) but allow delayed creation of the fence fd from a gl sync object
> (like the android egl extension allows).
> 
> I'm not sure yet how to best expose that really since just creating a
> fence from the implicit request attached to the batch might upset the
> interface purists with the mix in implicit and explicit fencing ;-) Hence
> why I think for now we should just do the eager fd creation at execbuf
> until ppl scream (well maybe not merge this patch until ppl scream ...).

Everything we do is buffer centric. Even in the future with random bits
of memory, we will still use buffers behind the scenes. From an
interface perspective, it is clearer to me if we say "give me a fence for
this buffer". Exactly the same way as we say "is this buffer busy" or
"wait on this buffer". The change is that we now hand back an fd to slot
into an event loop. That, to me, is a much smaller evolutionary step of
the existing API, and yet more versatile than just attaching one to the
execbuf.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre