[Intel-gfx] [PATCH] drm/i915/gem: Ensure aperture exists before setting domain to GTT

[Chris Wilson]

Quoting Stuart Summers (2019-11-19 21:30:32)
> mmap_gtt is already covered by a check for aperture presence.
> Also add the case to the gem_set_domain IOCTL to avoid this
> path for unsupported platforms.

It doesn't harm either, it will just mean in a place where it is neither
in the GPU nor in the CPU cache, same as it does today. The additional
flushes coming out of a GTT write domain should already be elided.

It is used internally to mean precisely that...

Userspace should already be weaning itself off set-domain altogether.
-Chris