[Intel-gfx] [PATCH 2/2] drm/i915/execlists: Use coherent writes into the context image

[Chris Wilson]

Quoting Chris Wilson (2018-08-16 12:11:49)
> That we use a WB mapping for updating the RING_TAIL register inside the
> context image even on !llc machines has been a source of consternation
> for every reader. It appears to work on bsw+, but it may just have been
> that we have been incredibly bad at detecting the errors.

Drat, I had hoped we had removed the conflicting mapping already.
-Chris