[Intel-gfx] [PATCH] drm/i915: Avoid reading through unaccessible PTEs during an error event

[Daniel Vetter]

On Tue, Nov 29, 2011 at 09:35:10AM +0000, Chris Wilson wrote:
> We need to sanity check that the buffer is actually bound into the
> mappable range of the GTT prior to reading it back through the GTT with
> the CPU. Fortuitously, the only buffers we have been interested in so
> far are constrained to be in the mappable region in order to handle
> potential relocations. However, this can be relaxed in future and given
> that the purpose is to read back following an error we should be extra
> careful and not assume everything is safe.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

For the lazy-gtt binding we need to also check whether the ptes are
correct (they should because we pin buffers with relocations as mappable).
I'll add that additional paranoia to my series.
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48