[Intel-gfx] [PATCH] drm/i915: Mask the ring->head offset using the ring->size

[Daniel Vetter]

On Tue, Nov 08, 2011 at 11:13:12PM +0000, Chris Wilson wrote:
> Rather than relying on the hardware to do this correctly, we can
> trivially do it ourselves.
> 
> This fixes a very reliable crash on d-i-n with all bits enabled during a
> cairo-trace replay. The symptoms of the crash is that we continue to
> write commands into the render ring buffer past the active head
> position, leading to undefined operations.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: stable at kernel.org

I guess this is just the usual "snb doesn't like being pushed to hard bug"
resulting in random crashes with confusing error_states. So I think I'll
drop this. Correct?
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48