The problem is *not* fixed by other updates at the time of writing the post---the fully updated system (16.04.1@thinkpad x220) has the same issue.
It is invariably happening when the "Switch user" capability is employed, in other words when a second instance of Xord is in use. The laptop actually is not completely locked up, it is still possible to get to a console by pressing Ctrl-Alt-F1, but one should wait for 20-30 seconds before the switch actually happens. Attempts to get back to X still result in an unresponsive computer, *BUT* if I put it into a sleep mode by issuing sudo pm-suspend from the console, I am able to get an X session unfrozen and continue to work. Seems like there is a bug in xorg-video-intel related to the second X without root privileges. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1583817 Title: WARNING: CPU: 1 PID: 865 at /home/kernel/COD/linux/drivers/gpu/drm/drm_irq.c:1326 drm_wait_one_vblank+0x1b0/0x1c0 [drm] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1583817/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
