CPU going very hot when connecting ac_adapter to laptop

I noticed that when I connect the AC_Adapter to my Thinkpad X1 carbon that the fan went full-throttle and CPU temp goes up to 76C and maybe more if I let it.
Using top I saw "systemd-udevd" maxing out 2 cores.
"udevadm monitor" tells me it's bluetooth/hci connected ....
It turns out using
"sudo systemctl stop systemd-udevd systemd-udevd-kernel.socket systemd-udevd-control.socket && sudo systemctl start systemd-udevd systemd-udevd-kernel.socket systemd-udevd-control.socket"
solves the problem ... until I connect again. Then it has to be run again or I simply dont run the start bit, but then I suspect I will not have bluetooth.

Hope this helps anyone having the same problem and ,maybe it'll be gone in newer kernel releases.

Edit:

Intrerestingly just using the stop command and resuming from suspend (using dpms) ..... if the touchpad is lost, using a previous solution:
"sudo modprobe -r psmouse;sudo modprobe psmouse" doesn't work. It requires a start of the sockets first. :face_with_raised_eyebrow:

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hum, this sounds like a very specific (hardware) issue :thinking: , FAQ section ?

so what is the process using this much cpu ?

It is (or was).
The laptop started having issues that it wouldn't shutdown through the OS i.e it kept booting up again spontaneously...as if the power button was stuck. :eyepopping:

If I did shutdown the machine by holding the power button for a long time, it wouldn't boot at all without the reset button (a small hole in the bottom) and the resetting time and date in the BIOS -- as if the battery had disconnected.

Eventually I opened the machine and found another (very, very small) button, similar to the reset button near one of the hinges and after pressing that (5 sec or so) --- everything was back to normal after the next reboot.
"Normal" meaning no more systemd-udevd hogging the CPU and proper shutdown procedures.:boogie: