[Intel-gfx] [PATCH 6/9] drm/i915: Allocate context objects from stolen

[Chris Wilson]

On Sat, Aug 10, 2013 at 11:25:46AM +0200, Daniel Vetter wrote:
> On Thu, Aug 08, 2013 at 02:41:08PM +0100, Chris Wilson wrote:
> > Once again, the CPU PAT bits are irrelevant when considering the GPU
> > cacheing, and context objects are never accessed from the CPU or
> > directly by userspace making them another ideal candidate to allocate
> > from stolen memory.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> I think this will break hibernate, since over hibernate stolen get some
> garbage. And userspace (and the gpu) probably don't expect garbage when
> trying to restore a hw context.

Same will be true for framebuffers, which we definitely want to use
stolen for. Suggests we will need to allocate temporaries across
hibernate or warn userspace that the contents are garbage.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre