[Intel-gfx] [PATCH] drm/i915/execlists: Avoid false matching of preemption when not enabled

[Chris Wilson]

Quoting Chris Wilson (2018-01-27 18:12:00)
> If we haven't enabled preemption for execlists, the PREEMPT_ID may be
> assigned to an ordinary user context, for which we should not falsely
> declare preemption complete!

Actually we are always allocating the preempt context. I had thought I
had followed Michal's suggestion to only allocate the preempt context
only when required. Ok, that explains why bdw wasn't exploding.
-Chris