Created attachment 111884 [details]
dmesg

==System Environment==
--------------------------
Regression: not sure

Non-working platforms: PNV

==kernel==
--------------------------
drm-intel-nightly/a719ac1cbb45e1af3f79a4e112cefef8bf47378e
commit a719ac1cbb45e1af3f79a4e112cefef8bf47378e
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Jan 6 09:09:24 2015 +0100

    drm-intel-nightly: 2015y-01m-06d-08h-08m-51s UTC integration manifest

==Bug detailed description==
-----------------------------
It sporadically fails on PNV with -nightly kernel, fail rate:1/5. 
kms_flip/dpms-vs-vblank-race-interruptible also sporadically fails.

output:
IGT-Version: 1.9-gc49a7e9 (i686) (Linux: 3.19.0-rc2_drm-intel-nightly_a719ac_20150107+ i686)
Using monotonic timestamps
Beginning modeset-vs-vblank-race-interruptible on crtc 21, connector 22
  1024x600 60 1024 1072 1104 1200 600 603 609 625 0xa 0x48 45000
.......
modeset-vs-vblank-race-interruptible on crtc 21, connector 22: PASSED

Beginning modeset-vs-vblank-race-interruptible on crtc 18, connector 28
  1024x768 60 1024 1048 1184 1344 768 771 777 806 0xa 0x40 65000
......................................................
modeset-vs-vblank-race-interruptible on crtc 18, connector 28: PASSED

Beginning modeset-vs-vblank-race-interruptible on crtc 21, connector 28
  1024x768 60 1024 1048 1184 1344 768 771 777 806 0xa 0x40 65000
....................................................Test assertion failure function run_test_step, file kms_flip.c:962:
Failed assertion: end - start > 0.9 * frame_time(o) && end - start < 2.1 * frame_time(o)
Last errno: 4, Interrupted system call
wait for two vblanks took 686 usec (frame time 16666.666667 usec)
Subtest modeset-vs-vblank-race-interruptible: FAIL (11.020s)

==Reproduce steps==
---------------------------- 
1. ./kms_flip --run-subtest modeset-vs-vblank-race-interruptible