[Intel-gfx] [PATCH 02/12] drm/i915: Defer transfer onto execution timeline to actual hw submission

[Chris Wilson]

On Thu, Nov 03, 2016 at 10:51:14AM +0000, Chris Wilson wrote:
> Yes. Worse is that the 2 comes from having different paths to this point
> with their own nesting pattern.

Not any more, that was a leftover from one version that managed to nest
signaling/execution.

The issue is 

	__i915_gem_request_submit -> fence_signal(rq->execute)

Then if we hook the submit fence onto an earlier execute fence, we hit
submit_notify() and try to acquire the engine->timeline again.

Hindsight says we cannot control the recursion there, so don't hook up
the fences like that (submit is not allowed to listen to execute).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre