[Intel-gfx] [PATCH] drm/i915: Revert "drm/i915/tgl: Wa_1607138340"

[Chris Wilson]

Quoting Tvrtko Ursulin (2020-01-08 16:19:54)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> This reverts commit 08fff7aeddc9dd72161b4c8fc27fbab12b4b9352.
> 
> For some yet unexplained reason not having this improves stability of some
> media workloads.
> 
> Promise is that the media hang will be root caused properly and in the
> meantime absence of this workaround is unlikely to cause problems.

I suspect this is shooting the messenger. The danger is that we rely on
FORCE_RESTORE for preemption, and so if this bit is triggering the issue,
their problem just becomes more sporadic.
-Chris