My PC is running Ubuntu 22.04, with KDE Plasma 5.24. When I select Sleep from the Application Launcher, it always starts t go to sleep, but then it seems like a 50-50 chance that it will stay asleep. Many times, it wakes right back up again within 10 seconds. If I try to make it sleep two or more times, sometimes it will eventually sleep but not always.

I’ve done some searching and cannot find a resolution to this.

It seems I’m not the only one too - https://superuser.com/questions/1795451/kde-plasma-does-not-sleep

  1. Is there a sure-fire way to tell Ubuntu KDE to sleep?

  2. If not, what are some things which might wake it up again?

Thanks!

  • e0qdk@reddthat.com
    0·
    8 months ago

    I don’t know about KDE in particular, but I’ve had problems with USB mice waking various Ubuntu systems when they’re not directly connected (i.e. there’s a hub or KVM in between it and the computer). The workaround I used for that was to remove the mouse input (e.g. by carefully pressing a physical button on the KVM) – which was good enough for me – but I think there is a programmatic way to block particular classes of input from waking the system if some device is waking your system inappropriately.

    Doing a quick search turned up this: https://askubuntu.com/questions/252743/how-do-i-prevent-mouse-movement-from-waking-up-a-suspended-computer – I can’t vouch for any of the specific techniques there though.

    Worth noting that while I had a problem with the mouse specifically, other hardware could be causing your system to wake up.

    • perishthethought@lemm.eeOPEnglish
      1·
      8 months ago

      Soooooooooo… thank you so much. I finally had time for trying out solutions here and your link to askubuntu helped me solve this. Specifically, the answer from Ali Hoza is what I tried first and it seems to work very well. I am copying that answer here for anyone else at Lemmy to try.

      The above solution (https://askubuntu.com/a/265389/1467620) works, but it is crude and, also it disables the keyboard wake, which is actually useful.

      A more granular alternative can be this: First, we start by enumerating the USB devices connected to the system:

      lsusb | sort

      from here, it’s pretty obvious which one is the mouse:

      Bus 002 Device 006: ID 046d:c52b Logitech, Inc. Unifying Receiver

      then we proceed with finding where the devices are mapped to:

      grep enabled /sys/bus/usb/devices/*/power/wakeup

      /sys/bus/usb/devices/2-1.2.6/power/wakeup:enabled /sys/bus/usb/devices/2-1.2.7/power/wakeup:enabled

      Finally, to figure out which is which, we use:

      dmesg | grep Logitech | grep -o -P "usb.+?\s"

      usb 2-1.2.7:

      at which point it’s pretty obvious which one needs to be disabled:

      sudo sh -c "echo 'disabled' > /sys/bus/usb/devices/2-1.2.7/power/wakeup"

      note: every time you need to echo as superuser, sh -c is necessary, or the system will not allow redirecting to a priviliged file.

      Then it’s just a matter of suspending the system and verifying that, while the mouse does not wake it, the keyboard will.

      this does not survive a system reboot, so either you need to re-run the last command, or add it to your .bashrc or .zshrc.

      This is something that has been annoying me on Ubuntu since when I installed 16.04, and probably there forever, I cannot understand why Canonical wouldn’t add this in the System Settings.

      Source: https://codetrips.com/2020/03/18/ubuntu-disable-mouse-wake-from-suspend/