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

[Daniel Vetter]

On Tue, Nov 29, 2011 at 07:02:06PM +0000, Chris Wilson wrote:
> 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>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48