3 Feb 2013

Broken connection to DiNovo bluetooth device: a solution

I have a Logitech DiNovo Mini (combined keyboard & touchpad), which at first worked just fine on my Gentoo laptop, Asus G50V, using the laptop's built-in bluetooth adapter, Bluez major version 4 (4.101-r5 today), and manual connection. Then I tried to connect the DiNovo to other devices, both without and with the USB-bluetooth-dongle that came with the DiNovo. Then I wanted it back to my laptop. There was a time when it worked only if I temporarily removed the battery from DiNovo. In the end, after several weeks if not months, it did not work anymore, at all. Blindly poking around, I now found how to fix it.

The DiNovo showed a green light, saying it got a connection, but on the laptop, all I could see was the device appearing and very soon disappearing in udev (confirmed with udevadm monitor). I tried to pair it again, many times, and while the pairing seemed to succeed, the device just did not work. I also installed blueman, which indicated the same: when I touched the DiNovo, it connected, and was immediately disconnected. In the system log I got:
bluetoothd[280]: Refusing input device connect: Operation already in progress (114)
bluetoothd[280]: Refusing connection from ##:##:##:##:##:##: setup in progress
(bluetoothd:280): GLib-WARNING **: Invalid file descriptor.
Ok, so is it trying to connect twice for some odd reason? Where is the state kept? Could I manually fix it?

Apparently, I could. In the /var/lib/bluetooth/*/ directory I saw several files that seemed to be about the bluetooth settings on my Gentoo. Not knowing anything about how Bluez works, I looked at the files there, to see if I could spot something suspicious. Luckily they were all plain-enough text files, so I did spot something.

The file /var/lib/bluetooth/*/spd had two lines with my DiNovo's device address on it. The first line was a long one, the second line short. Not knowing what I'm doing, I stopped the bluetooth service, removed the short line, and restarted the bluetooth service. Like magic, the DiNovo started working again, connecting automatically. No errors in the system log anymore, either.

I have not used the DiNovo much after the repair yet, remains to be seen if I broke anything, but so far so good. Apparently when I was playing around with the DiNovo, somehow that file got a second entry for the same device, and caused malfunction. Is it my fault or a bug, I do not know. Googling did not give any helpful hints on solving this, so I am recording this note here, hoping it helps someone.

-- A note, barely readable, scratched with a broken SD-card on the wall of a passageway in the huge, monster crawling dungeon they call the Intternets.

No comments:

Post a Comment