[PATCH 1/2] drm/i915: Make bonded requests be alone in ELSP ports

[Chris Wilson]

Quoting Tvrtko Ursulin (2020-05-20 14:24:12)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Mark bonded request pairs as single port submission to avoid potential
> deadlocks due scheduling inversions.

Such a deadlock would be a bug in the code. We control the ordering of
submission such that requests are submitted in order across engine.
-Chris