As requested, booted using battery power with setting "auto" in /lib/udev/rules.d/99-laptop-mode.rules. Then changed setting back to "force" and plugged in an external USB HDD (Transcend StoreJet).
The USB device seemed to be mounted successfully and I could write to it.
As requested, booted using battery power with setting "auto" in /lib/udev/ rules.d/ 99-laptop- mode.rules. Then changed setting back to "force" and plugged in an external USB HDD (Transcend StoreJet).
The USB device seemed to be mounted successfully and I could write to it.
Dmesg output attached.