drm/i915: Disable GPU semaphores by default
authorChris Wilson <chris@chris-wilson.co.uk>
Fri, 4 Mar 2011 18:48:03 +0000 (18:48 +0000)
committerChris Wilson <chris@chris-wilson.co.uk>
Mon, 7 Mar 2011 11:00:59 +0000 (11:00 +0000)
commita1656b9090f7008d2941c314f5a64724bea2ae37
tree7fec97b2bff698d6d5d952e6c0ae0950488e9fc2
parent91355834646328e7edc6bd25176ae44bcd7386c7
drm/i915: Disable GPU semaphores by default

Andi Kleen narrowed his GPU hangs on his Sugar Bay (SNB desktop) rev 09
down to the use of GPU semaphores, and we already know that they appear
broken up to Huron River (mobile) rev 08. (I'm optimistic that disabling
GPU semaphores is simply hiding another bug by the latency and
side-effects of the additional device interaction it introduces...)

However, use of semaphores is a massive performance improvement... Only
as long as the system remains stable. Enable at your peril.

Reported-by: Andi Kleen <andi-fd@firstfloor.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33921
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
drivers/gpu/drm/i915/i915_drv.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem_execbuffer.c