Chris Wilson 34730fed9f drm/i915: Ignore stuck requests when considering hangs ... If the engine isn't being retired (worker starvation?) then it is possible for us to repeatedly observe that between consecutive hangchecks the seqno on the ring to be the same and there remain unretired requests. Ignore these completely and only regard the engine as busy for the purpose of hang detection (not stall detection) if there are outstanding breadcrumbs. In recent history we have looked at using both the request and seqno as indication of activity on the engine, but that was reduced to just inspecting seqno in commit cffa781e59 ("drm/i915: Simplify check for idleness in hangcheck"). However, in commit dcff85c844 ("drm/i915: Enable i915_gem_wait_for_idle() without holding struct_mutex"), I made the decision to use the new common lockless function, under the assumption that request retirement was more frequent than hangcheck and so we would not have a stuck busy check. The flaw there was in forgetting that we accumulate the hang score, and so successive checks seeing a stuck request, albeit with the GPU advancing elsewhere and so not necessary the same stuck request, would eventually trigger the hang. Fixes: dcff85c844 ("drm/i915: Enable i915_gem_wait_for_idle()...") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20160820145408.32180-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>		2016-08-22 13:09:11 +01:00
..
drm	drm/i915: Ignore stuck requests when considering hangs	2016-08-22 13:09:11 +01:00
host1x	gpu: host1x: Remove useless local variable	2016-06-23 11:59:33 +02:00
ipu-v3	gpu: ipu-v3: rename CSI client device	2016-08-08 11:44:20 +02:00
vga	vga_switcheroo: Sphinxify docs	2016-07-12 16:14:36 +02:00
Makefile