Comment 84 for bug 1384342

@meira Sorry, somehow I had missed Dirk's comment. According to that, 3.16.0-33 should be fixed. In which case, you can try the latest mainstream kernel. The rest of the comment #71 might apply:

If you can still reproduce it after that, then note from dri-devel list:

"If you can reproduce this somehow, please boot with drm.debug=0xe and
attach the complete dmesg up to the WARNING. We seem to loose track of
pageflips under obscure circumstances sometimes. We have more band-aids
queued up, but fixing the underlying issue would be better ofc."

- http://permalink.gmane.org/gmane.comp.video.dri.devel/112025