[Intel-gfx] [PATCH 2/6] drm/i915/gtt: Don't restore the non-existent PDE for GGTT

[Chris Wilson]

Quoting Joonas Lahtinen (2018-06-01 13:56:56)
> On Fri, 2018-06-01 at 10:35 +0100, Chris Wilson wrote:
> > On resume, we have to rewrite all the PDE entries for gen7 ppgtts. If we
> > switch on full-ppgtt, there is then one address space with no PDE, the
> > GGTT. Currently under aliasing-ppgtt, the GGTT address space does have
> > an associated ppgtt and so the restore works just fine. We would have a
> > similar problem if we tried disabling aliasing-ppgtt
> > (i915.enable_ppgtt=0). So skip the empty ppgtt, as being non-existent it
> > doesn't need restoring.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> 
> Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Pushed the first pair as simple standalone NULL pointer fixes. Thanks
for the review,
-Chris