Comment 6 for bug 1810797

And here is a kernel snap for testing: http://people.canonical.com/~ppisati/lp1810797/dragonboard-kernel_4.15.0-43.46~lp1810797_arm64.snap

hcitool has a problem accessing hci0 on Ubuntu core (at least, in my tests), use bluetoothctl instead:

p-pisati@localhost:~$ sudo bluetoothctl
[NEW] Controller 00:00:00:00:5A:AD localhost.localdomain [default]
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# power on
[CHG] Controller 00:00:00:00:5A:AD Class: 0x00100000
Changing power on succeeded
[CHG] Controller 00:00:00:00:5A:AD Powered: yes
[bluetooth]# scan on
Discovery started
[CHG] Controller 00:00:00:00:5A:AD Discovering: yes
...