[Mesa-dev] [PATCH 0/10] Tessellation shaders for Gen7/7.5.

[Jordan Justen]

On 2015-12-24 17:34:18, Kenneth Graunke wrote:
> This morning, I woke up and somehow "knew" what was causing my HS GPU hangs
> on Gen7/7.5.  It turns out I was (completely) wrong, but through some
> miraculous series of illogical leaps, I arrived at a solution anyway.
> 
> I don't honestly know how I got it working on Christmas Eve after
> failing to figure it out for months on end.  After exhausting every bit
> of documentation and every tool available, and finding zero information,
> somehow randomly flailing in the dark resulted in a solution, today of
> all days.  Honestly, I had pretty much no hope for figuring this out,
> so I'm relieved to have it working at last...
> 
> It turns out that setting interleave on the EOT URB write does bad things.
> Fixing this fixed all the GPU hangs when releasing inputs one at a time,
> I then added back the ability to release inputs in pairs, which caused
> more GPU hangs.  It turned out I needed to be more careful and enable
> both halves.

Wow. That sucks that it wouldn't hang when a single test was run, and
the simulator didn't help either. :(

Nice work debugging it though!

Series Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>