Add me to the list of those having this issue, but also have a partial fix. I am running a Thinkpad P50 with Nvidia display adapter. 18.04 was great, never any issues with suspend or resume. I upgraded to 20.04 a couple of weeks ago and immediately began encountering the reboot on resume issue. Suspend worked fine, the LED on the cover dimmed and brightened to indicate it was asleep, external displays went into power save, etc. But when trying to resume it rebooted from scratch every time.
I found this article https://itsfoss.com/ubuntu-close-lid-suspend/ and followed the steps in it. To my surprise, pm-utils was not installed, so I installed it. I also made the suggested edits to /etc/systemd/logind.conf plus a few more, my edited file is below. After these steps, I can now resume from suspend successfully. My laptop display remains dark but the external monitors come on and show the desktop. If I logout and back in then all is fine and all displays work. Here is my edited config file: [Login] #NAutoVTs=6 #ReserveVT=6 #KillUserProcesses=no #KillOnlyUsers= #KillExcludeUsers=root #InhibitDelayMaxSec=5 HandlePowerKey=suspend HandleSuspendKey=suspend #HandleHibernateKey=hibernate HandleLidSwitch=suspend HandleLidSwitchExternalPower=suspend HandleLidSwitchDocked=suspend PowerKeyIgnoreInhibited=no SuspendKeyIgnoreInhibited=no #HibernateKeyIgnoreInhibited=no LidSwitchIgnoreInhibited=no #HoldoffTimeoutSec=30s #IdleAction=ignore #IdleActionSec=30min #RuntimeDirectorySize=10% #RemoveIPC=yes #InhibitorsMax=8192 #SessionsMax=819 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1848771 Title: Reboot after resume from suspend (deep) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1848771/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
