Could you try updating the BIOS firmware, and see whether this issue is
still reproducible?

I cannot observe the issue with BIOS firmware version 1.13.0 with
docking station DA310.

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1944409

Title:
  Systemd uses CPU after wakeup due to power_supply BAT0 (battery)
  continued polling

Status in OEM Priority Project:
  New
Status in systemd package in Ubuntu:
  Confirmed

Bug description:
  My setup:
   - Dell Latitude 7520
   - Dell WD15 USB C docking station
   - Ubuntu 20.04.3
   - systemd 245.4-4ubuntu3.13
   - uname -a:
  Linux CLIFMI085 5.13.0-1012-oem #16-Ubuntu SMP Tue Sep 7 09:23:08 UTC 2021 
x86_64 x86_64 x86_64 GNU/Linux

  I leave my laptop docked and, after waking it up from sleep, the fans
  start blowing. After a quick inspection with top/htop, I always see
  /usr/lib/systemd/systemd-udev consuming 50+% of my CPU.

  After a quick search, I discover that I can use `udevadm monitor` to
  check what device is making all this fuss, and this is the output:

  UDEV  [92591.827159] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92591.873819] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92591.920022] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92591.967005] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.018200] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.068351] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.115100] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.166201] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.213318] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.261046] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.308824] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.356577] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.403766] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92592.451164] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)

  As you can see, the battery status is being polled every 0.05s. To fix
  this, I just need to restart the service with:

  sudo systemctl restart systemd-udevd systemd-udevd-kernel.socket
  systemd-udevd-control.socket

  Afterwards, this is the output of `udevadm monitor`:

  KERNEL[92739.612371] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92739.646888] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  KERNEL[92741.076823] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92741.099370] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  KERNEL[92742.539438] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)
  UDEV  [92742.573812] change   
/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0 (power_supply)

  As you can see, the battery is now being polled every ~1.5s, which is
  fine.

To manage notifications about this bug go to:
https://bugs.launchpad.net/oem-priority/+bug/1944409/+subscriptions


-- 
Mailing list: https://launchpad.net/~touch-packages
Post to     : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to