Unable to Resume after Screen has Locked
I am not able to resume a session after the screen has been locked for a long time. This is not a new problem. Similar questions have been posted in the past, two of which are listed below.
Black Screen after Screen Lock
Screens don't work after shutting off
This problem has also been reported to Ubuntu, who have provided the following wiki link for guidance.
DebuggingKernelSuspendHibernateResume
One cause of the problem that is noted in DebuggingKernelSuspendHibernateResume is when the swap file is encrypted. This will automatically happen if one decides to encrypt the /home directory during installation. As I did not choose this option, I don't believe that my swap file is encrypted, however, I have encrypted the home directories of the Windows XP partition which resides on a separate drive. Not sure if this is an issue but, how would I be able to determine whether or not the swap space partiion under Ubuntu has been encrypted?
The solution noted by @cprofitt in his/her answer to Screens don't work after shutting down mentions modifying xorg.conf, and possibly grub. Unfortunately, I cannot locate the xorg.conf file on my system. It is not in the typical locations that one would expect to find it (e.g. /etc/X11). Also, I am not certain how to modify grub.
As a workaround, I have turned off screen locking, however, I would really like to solve this problem. My configuration is as follows:
Ubuntu 11.10
VGA compatible controller: Intel Corporation 82865G Integrated Graphics Controller (rev 02)
Also note that I have a KBM switch that switches between the PC and a Mac OS X laptop. I know for a fact that this is not a problem since, I am still able to switch to my laptop when the problem occurs. Furthermore, I have physically connected a keyboard and mouse to the PC where I have installed Ubuntu, and the problem still occurs.
Solution 1:
If you don't want to change screensavers (not sure why you wouldn't), there's another litle workaround.
It's a bit irritating, but I found that you can fanagle the screen lock by switching between terminals (ctrl-alt-F1, ctrl-alt-F7, ctrl-alt-F6, ctrl-alt-F7) until the correct login widgets finally show up. For me it passes from background screen with status bar, to background screen, to black screen screensaver -- after which I can wake up my screen and enter my session password.
Not sure why it works, and sometimes it takes a bit longer than others, but it works consistenly, eventually, and every time.
Now, I will go install xscreensaver....
Solution 2:
This is the same issue as: https://askubuntu.com/questions/72692/system-freezes-after-the-automatic-screen-saver-kicks-in
OR https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/882893
This is a regression bug in Gnome3 screensaver, and affects the Intel 82865G integrated graphics (or similar) devices.
BEST WORKAROUND is to replace gnome-screensaver with xscreensaver.
Linked Question:
- How can I change or install screensavers?