Ben Gamari f65d94211e drm/i915: Add hangcheck timer ... We set a periodic timer to check on the GPU, resetting it every time a batch is completed. If the timer elapses, we check acthd. If acthd hasn't changed in two timer periods, we assume the chip is wedged. This is implemented in such a way that it leaves the option open to employ adaptive timer intervals in the future. One could wait until several timer periods have elapsed before declaring the chip dead. If the chip comes back after several periods but before the "dead" threshold, the timer interval or dead threshold could be raised. It is important to note that while checking for active requests, we need to account for the fact that requests are removed from the list (i.e. retired) in a deferred work queue handler. This means that merely checking for an empty request_list is insufficient; the list could be non-empty yet the GPU still idle, causing the hangcheck timer to incorrectly mark the GPU as wedged (it took me a while to figure that out---sigh...) Signed-off-by: Ben Gamari <bgamari.foss@gmail.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>		2009-09-17 14:36:01 -07:00
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drm	drm/i915: Add hangcheck timer	2009-09-17 14:36:01 -07:00
Makefile	drm: reorganise drm tree to be more future proof.	2008-07-14 10:45:01 +10:00