How to resume Ubuntu 18.04 after hibernate?
Solution 1:
xenoid kindly pointed out a generally helpful article on the ubuntu wiki.
Dead, blank, or black screen on resume In some cases, a machine can hibernate just fine, and resume without issue, with the exception of waking up to a blacked-out screen. In other words, the computer is running just fine, but the display appears dead.
They recommend adding nomodeset to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub.
Because I like verbose boot, I did not specify quiet splash as they did in their example, and because I followed this guide I already had GRUB_CMDLINE_LINUX_DEFAULT="resume=UUID=<my uuid>". So in the end my line looks like this:
GRUB_CMDLINE_LINUX_DEFAULT="nomodeset resume=UUID=93232136-5a6d-4ffc-b40d-809ccead48df"
After changing that, you need to run
sudo update-grub2
(which happens to do the exact thing as sudo update-grub). And then
reboot
Now systemctl hibernate should work.
This question asks the same thing you are wondering right now:
- What exactly am I doing? Why does it help?
- Can I do something to avoid doing these steps?
The answer suggests to "install suitable video drivers". That may well indicate why I had to add nomodeset this time, but not last time I tried to set up hibernate - my audio driver is also broken, so that could be related (though I don't know why this happened).
It turns out this solution broke my audio card detection and my brightness controls. See here for more info. As of July 2020 it seems like a kernel update or something has fixed this issue for me though.
systemctl suspend does now "work" as well... but for some reason the screen stays on. It's mostly black, but you can tell because there's a white underscore at the top left corner.