I don't have any BIOS update available; as I said, my laptop (Dell Latitude 7520) is fully updated.
$ sudo dmidecode -s bios-version 1.6.1 $ fwupdmgr get-updates | grep "Current version" -B2 Devices with no available firmware updates: • UEFI Device Firmware • UEFI Device Firmware • UEFI dbx • VMM3332 inside Dell WD15/TB16/TB18 wired Dock │ │ Device ID: 71b677ca0f1bc2c5b804fa1d59e52064ce589293 │ │ Summary: NVM Express Solid State Drive │ │ Current version: 21112012 -- └─System Firmware: │ Device ID: 5ecfc78eb81da0c1a2ab9baa1510f0c269ea1b9b │ Current version: 1.6.1 -- 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
