I take that back, it seems to have been caused by Chromium all along (more specifically either #threaded-compositing-mode or #deadline- scheduling), despite those glitches appearing outside of Chromium too. Sot it's a Chromium bug, but I'm too lazy to debug this further (the issue goes away with those configuration flags set to default) so I'll just mark this as invalid.
** Changed in: xorg-lts-trusty (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1345573 Title: Horizontal lines flashing on screen briefly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-lts-trusty/+bug/1345573/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs