Dear Maintainer,

New Logitech K380 keyboard. Bluetooth would pair with it, but not
correctly and/or not connect. Tried via KDE/bluedevil,
Gnome/gnome-bluetooth, bluetoothctl. The
file /var/lib/bluetooth/<interface addr>/<device addr>/info was
created, but the [LinkKey] section was missing, no matter what
interface I used to pair, so no "Key=" or "Type=" entries. (Also, the
info file created via bluedevil had more entries than the version
created via Gnome, which was minimal). Setting "Trusted=true" in that
file did not fix the problem. As a workaround I did the following: boot
windows8.1, pair the keyboard (no problems), go into the registry and
find the 16 byte key value, then in debian manually add "[LinkKey]"
line and "Key=xxxxxxxxxxxxxxxx" and "Type=4" and "PINLength=0" entries
in the info file, then after that it has worked fine.

Note I also am using a bluetooth mouse with the same system, had no
problems pairing it with debian, and used its info file as a model for
the keyboard one. When the mouse was paired, the debian version was the
same, have only had a few updates since then not related to bluetooth.

Maybe relevant: this particular keyboard has 3 buttons to remember
separate pairings with 3 different devices. Same problem no matter
which button I used to pair it, and if I had it paired with windows on
button 1, then an unsuccessful pairing with debian on button 2 would
affect the button 1 pairing somehow so that windows would say it was
paired but wouldn't connect (had to remove/re-pair).