[Intel-gfx] [PATCH 28/43] drm/i915: Handle unmappable buffers during error state capture

[Daniel Vetter]

On Wed, Dec 14, 2011 at 04:46:48PM -0200, Eugeni Dodonov wrote:
> On Wed, Dec 14, 2011 at 10:57, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> 
> > From: Chris Wilson <chris at chris-wilson.co.uk>
> >
> > As the buffer is not necessarily accessible through the GTT at the time
> > of a GPU hang, and capturing some of its contents is far more valuable
> > than skipping it, provide a clflushed fallback read path. We still
> > prefer to read through the GTT as that is more consistent with the GPU
> > access of the same buffer. So example it will demonstrate any errorneous
> > tiling or swizzling of the command buffer as seen by the GPU.
> >
> > This becomes necessary with use of CPU relocations and lazy GTT binding,
> > but could potentially happen anyway as a result of a pathological error.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> Reviewed-by: Eugeni Dodonov <eugeni.dodonov at intel.com>

I've got fed up with my kernel's all dying while testing cs prefetch
behaviour, so I've included this patch in the current pile. Should also
make qa's job a bit easier because the test is already included in i-g-t,
but the fix won't be ready for the next -next cycle.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48