#7 output was already attached there, just grepped for brevity. The
first lines where confusing me though, I've now upgraded the system BIOS
from 1.6.1 to 1.12.2. 1.13 seems available on the official site, I'll
report back ASAP on the results of the upgrade.

-- 
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