I got the same bug. If hciuart.service was started before /dev/serial1 is created, it fails. Fixed by adding systemd override with "Requires" directive:
# systemctl cat hciuart # /lib/systemd/system/hciuart.service [Unit] Description=Configure Bluetooth Modems connected by UART ConditionFileNotEmpty=/proc/device-tree/soc/gpio@7e200000/bt_pins/brcm,pins After=dev-serial1.device [Service] Type=forking ExecStart=/usr/bin/btuart [Install] WantedBy=multi-user.target # /etc/systemd/system/hciuart.service.d/override.conf [Unit] Requires=dev-serial1.device <---- fix of this problem ---- Here's what documentation says: After=: The units listed in this directive will be started before starting the current unit. This does not imply a dependency relationship and one must be established through the above directives if this is required. Requires=: This directive lists any units upon which this unit essentially depends. If the current unit is activated, the units listed here must successfully activate as well, else this unit will fail. These units are started in parallel with the current unit by default. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1929791 Title: Bluetooth does not start if system boots from USB To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-raspi2/+bug/1929791/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
