[Intel-gfx] [PATCH v2] drm/i915: Stop discarding GTT cache-domain on unbind vma

[Chris Wilson]

On Fri, Apr 24, 2015 at 07:45:23AM +0100, Chris Wilson wrote:
> v2: Akash worried that we were discarding the serialisation point with
> outstanding GTT writes before doing the unbind, so restore the wmb() for
> the writes. We only lose the write domain now, and not both - 1 one
> sided barrier now, rather than 2 full barriers previously.

More thought says that worrying about outstanding kernel writes (which I
was since we explicitly flush userspace mmaps) is pointless since we use
iomap_atomic - i.e. we also explicitly flush writes upon unmap, inside
pwrite, reloc etc.

So we can go back to v1! :)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre