The issue is first found on other platform during enablement, and the fix is landed in BIOS. Latitude 7520 has no problem with the BIOS version we certified, however, the regression should be caused by BIOS upgrade. Therefore, I assume the latest BIOS should contain fix for it. As I know, the issue should be observed whenever adapter is attached, if you can't see it, the issue should be fixed in the latest BIOS.
You can still monitor few days or do whatever experiment you'd like to do, until you think the issue is indeed fixed. Again, thanks for reporting the issue. -- 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