https://bugs.freedesktop.org/show_bug.cgi?id=89887
--- Comment #9 from Christian König deathsimple@vodafone.de --- (In reply to Marek Olšák from comment #8)
I will close this as NOTABUG. Please try again with a lower instance count and make sure it finishes in 10 seconds.
Alternatively use the kernel parameter radeon.lockup_timeout=20000 to increase the timeout to 20 seconds.