[Intel-gfx] [PATCH 2/2] drm/i915/gtt: Don't check PPGTT presence on PPGTT-only platforms

[Chris Wilson]

Quoting Michał Winiarski (2019-07-02 12:31:49)
> We missed one place where we check PPGTT-only platform for PPGTT
> presence. Let's remove it.
> While I'm here let's assert that this particular code is never called on
> pre-gen8 platforms.
> 
> References: 4bdafb9ddfa4 ("drm/i915: Remove i915.enable_ppgtt override")
> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

Hazy memory says that disabling pat (making everything uncached) was
desired for some early sanity checks. Hmm, there might be scope in here
for some selftests (to which I mean there is definitely room for more!)
-Chris