@Peter:
I had the same issue after upgrading to 15.04. and this kernel module solved it. Maybe it helps in your case as well?
I added
hid-logitech-hidpp to /etc/initramfs-tools/modules
then sudo update-initramfs -u
as described here: http://askubuntu.com/questions/613139/ubuntu-15-04-usb-devices-powered-off-at-encrypted-root-password-prompt
@Peter:
I had the same issue after upgrading to 15.04. and this kernel module solved it. Maybe it helps in your case as well?
I added
hid-logitech-hidpp -tools/ modules
to
/etc/initramfs
then
sudo update-initramfs -u
as described here: http:// askubuntu. com/questions/ 613139/ ubuntu- 15-04-usb- devices- powered- off-at- encrypted- root-password- prompt