Bluetooth doesn't work after resuming from sleep, Ubuntu 18.04 LTS
update bluez to >=5.28.2
18.04 ships with a buggy bluez package for now; newer version is available from this PPA: https://launchpad.net/~bluetooth/+archive/ubuntu/bluez:
sudo add-apt-repository ppa:bluetooth/bluez
sudo apt install bluez
workaround for buggy Bluetooth applet (Unity specific?)
This is probably the issue @solstice mentioned - BT menu applet doesn't let me enable Bluetooth after resuming from sleep. No matter if the toggle switch is off or on, the BT icon is disabled, and rfkill output doesn't change:
$ rfkill list
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
12: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
You can toggle BT manually by running (substitute your own ID):
rfkill block 12
rfkill unblock 12
and BT applet should pick it up correctly now. At this point, you should be able to connect to your devices. For now I've hacked it together using a script that does this automatically after resume:
$ cat /lib/systemd/system-sleep/bt
#!/bin/sh
case $1 in
post)
sleep 5
rfkill block `rfkill list | grep hci | cut -d: -f1`
sleep 1
rfkill unblock `rfkill list | grep hci | cut -d: -f1`
;;
esac
The ID number next to hci0 in rfkill list output seems to increment after every suspend/resume. Disabling/enabling BT using the BT menu should change the output ('soft blocked: yes' for BT disabled via menu), but it doesn't. My guess is that the applet remembers the wrong device ID and is thus trying to enable a device that no longer exists.
For me this problem can be resolved by running
sudo service bluetooth restart
after waking from sleep
I run 19.04 and have this issue. I have a BT mouse so it really is annoying.
To enhanced @hinxnz answer:
Open an new file:
sudo nano /lib/systemd/system-sleep/bt
Paste in this script:
#!/bin/sh
case $1 in
post)
modprobe -r btusb
sleep 1
service bluetooth restart
sleep 1
modprobe btusb
;;
esac
An finally make it executable
chmod +x /lib/systemd/system-sleep/bt