Starting subtest: absolute-wf_vblank
(kms_flip:1752) CRITICAL: Test assertion failure function wait_for_events, file ../tests/kms_flip.c:1037:
(kms_flip:1752) CRITICAL: Failed assertion: ret > 0
(kms_flip:1752) CRITICAL: select timed out or error (ret 0)
The CI Bug Log issue associated to this bug has been updated.
### New filters associated
* SKL: igt@kms_flip@absolute-wf_vblank - fail - select timed out or error (ret 0)
Reproducible: 1.7% http://gfx-ci.fi.intel.com/cibuglog-ng/. No failures in recent history: bug_history :http://gfx-ci.fi.intel.com/cibuglog-ng/results/all?query=test_name%3D%27igt%40kms_flip%40absolute-wf_vblank%27
What does the sub-test do: The sub-test absolute-wf_vblank tests a set no. of vblanks after doing a flip and checks if the vblank events are received by the userspace in a tolerable limit of time. This is one of many sub-tests that check various combination of flip done and vblank events and make sure that the events are received timely.
The sub-test does a flip and waits for flip-done event, before going to the actual test for absolute vblanks. After receiving the flip-done event, the sub-test runs in a tight loop for a given 'n' seconds. In 'n' seconds, it repeatedly waits for 10 vblanks and checks if the time in which these are received is less than some tolerable limit in msecs. This is repeated for each Pipe and (connected) Connector combination.
The issue: The issue is quite rare, and difficult to reproduce. After the flip, the test waits for flip-done event using select command on the drm_fd, but is not able to get the event. Finally the test times out, resulting in the failure.
Since the reproducible rate is very less, and the test is not seen to fail in recent history for all platforms, this issue is suggested to be closed.
Apologize for the above history links.
Here is correct link from the recent history:
It is seen to be passing for most platforms.