[Intel-gfx] [PATCH 3/3] drm/i915: add fences to the request struct

[Chris Wilson]

On Wed, Dec 03, 2014 at 11:49:07AM -0800, Jesse Barnes wrote:
> This simplifies the sync code quite a bit.  I don't think we'll be able
> to get away with using the core fence code's seqno support, since we'll
> be moving away from simple seqno comparisions with the scheduler and
> preemption, but the additional code is pretty minimal anyway, and lets
> us add additional debugging as needed, so it's probably fine to keep
> either way.
> 
> We still need to add support for other rings here; we ought to be able
> to do that with the timeline field of the ioctl (which will include
> other "rings" like the display flip queue for example).

I am ambivalent about this. I don't think migrating i915_request over to
use the heavyweight fence primitives is a good idea, so see little value
in embedding the struct fence inside i915_request vs a small bookkeeping
struct referencing i915_request.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre