[Intel-gfx] [RFC PATCH 2/2] drm/i915: truncate zero dumps in error state

[Chris Wilson]

On Fri, Apr 19, 2013 at 11:16:11AM +0300, Jani Nikula wrote:
> It seems the error state often contains plenty of zero data [citation
> needed]. It's also fairly big. Truncate more than (arbitrarily chosen)
> three consecutive zero values:
> 
> 00000000 :  0b640001
> 00000004 :  000047f8
> 00000008 :  00002044
> 0000000c :  00000000
> 00000010 :  00000000
> 00000014 :  00000000 ...
> 00000024 :  01000000
> 00000028 :  13000001
> 
> It could be prettier and more informative, but care must be taken not to
> confuse intel_error_decode. I didn't put much effort into either before
> getting an ack on the idea.

This would be safer if it were only applied to rings and after
MI_BATCHBUFFER_END in batches. In the larger 3DSTATE commands, we can
indeed end up with large blocks of zeroes and the decoder relies on the
correct count to skip instructions.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre