Bug#846941: linux-image-4.8.0-1-amd64-unsigned: ThinkPad X220: hibernating with screen turned off (screensaver) causes it to remain off until reboot

[Benjamin Barenblat <bbaren@mit.edu>]

Control: retitle -1 ThinkPad X220: suspending or hibernating with screen turned off causes it to remain off until reboot
Control: notfound -1 linux/3.16+63
Control: found -1 linux/4.9+80

On Sun, Dec  4, 2016 at  5:02:52 PM, Ivan Krylov <krylov.r00t@gmail.com> wrote:
> When I hibernate my machine with screen turned on
> (e.g. xfce4-session-logout --hibernate), it wakes up as expected.
> However, if something turns the screen off before that
> (e.g. XScreenSaver activating), on wakeup the screen is unresponsive,
> but the remaining system works (I can ssh into machine and play music,
> etc).

I can reproduce this on my X220 tablet with linux-image-4.9.0-3-amd64.

  1. Run `xset dpms force off` to shut the display off.
  2. Close the lid, suspending the machine.
  3. Reopen the lid, bringing the machine back up.

At this point, the display is off and will remain so until I reboot. The
machine is otherwise functional; if I leave a terminal open before
running these steps, I can type `systemctl reboot`, and the system will
reboot.