PC auto connects itself to mobile phone as an audio device

[Sergio Callegari]

I have an android phone (2.3.6) and a DELL E6500 running kubuntu precise.

The phone has been paired to the computer in order to use bluetooth for internet access (as I prefer this to the wifi hotspot to do tethering).

Unfortunately, at this point, whenever the phone is close to the computer, the two autoconnect for audio transfer and it gets hard to use the phone, as the audio is routed to the computer (that incidentally does not seem able to propagate it to its speakers and microphone).

Is there some way to prevent PC with bluez to announce itself as a headset or audio device and autoconnect for this?

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: bluez 4.98-2ubuntu7
ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18
Uname: Linux 3.2.0-25-generic x86_64
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Thu Jun 14 10:30:42 2012
InstallationMedia: Kubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
InterestingModules: rfcomm bnep btusb bluetooth
MachineType: Dell Inc. Latitude E6500
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-25-generic root=/dev/mapper/group00-root ro quiet splash vt.handoff=7
SourcePackage: bluez
UpgradeStatus: Upgraded to precise on 2012-05-01 (43 days ago)
dmi.bios.date: 08/19/2010
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A24
dmi.board.name: 0W612R
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA24:bd08/19/2010:svnDellInc.:pnLatitudeE6500:pvr:rvnDellInc.:rn0W612R:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude E6500
dmi.sys.vendor: Dell Inc.
hciconfig:
 hci0: Type: BR/EDR Bus: USB
  BD Address: 00:26:5E:E6:63:86 ACL MTU: 1021:8 SCO MTU: 64:8
  UP RUNNING PSCAN ISCAN
  RX bytes:3102 acl:60 sco:0 events:109 errors:0
  TX bytes:2423 acl:63 sco:0 commands:62 errors:0
mtime.conffile..etc.bluetooth.rfcomm.conf: 2010-10-18T08:47:12.295957
syslog:

[Mathieu Trudel-Lapierre (cyphermox)]

You can add "Source" to the Disable= list in /etc/bluetooth/audio.conf.

However, the necessary links between the sources and sinks should not be getting done automatically. Could you please attach the output of 'pactl list short modules' ?

[Sergio Callegari (callegar)]

Here it is:

0 module-device-restore
1 module-stream-restore
2 module-card-restore
3 module-augment-properties
4 module-alsa-card device_id="0" name="pci-0000_00_1b.0" card_name="alsa_card.pci-0000_00_1b.0" namereg_fail=false tsched=yes ignore_dB=no deferred_volume=yes card_properties="module-udev-detect.discovered=1"
5 module-udev-detect
6 module-bluetooth-discover
7 module-esound-protocol-unix
8 module-native-protocol-unix
9 module-default-device-restore
10 module-rescue-streams
11 module-always-sink
12 module-intended-roles
13 module-suspend-on-idle
14 module-console-kit
15 module-position-event-sounds
16 module-filter-heuristics
17 module-filter-apply
18 module-switch-on-port-available
19 module-device-manager do_routing=1
20 module-x11-bell display=:0 sample=bell.ogg
22 module-cli-protocol-unixù

Phone says "connesso a telefono e audio multimediale" (connected as phone and multimedia audio) .
You see (hear) that the phone is connected because the clicking feedback from key pressed on the virtual keyboard disappear (all acoustic output apart from phone calls gets apparently routed to the PC).
This connection happens automatically.

As a matter of fact, I now recall that also my previous phone (a Nokia C2-01) attempted auto-connecting to the PC after the upgrade to precise, but that phone used to fail, give an error message and be happy.

[Mathieu Trudel-Lapierre (cyphermox)]

I'm not seeing anything special in the module list that would hint at autoconnection of the new bluetooth devices, unless that's a new feature in a new PulseAudio or if you had compiled it yourself. Regardless, I can't reproduce this here with my laptop and Android phone (though it's using ICS)

It's still unknown to me why it autoconnects and reacts that way; since I'm not seeing that behavior. In all cases I'd expect that the sources and sinks would have to be connected in PulseAudio, which currently should mean manual intervention by a user, and something that doesn't survive a reboot.

On your phone, you may be able to go into the "advanced" settings for the bluetooth connection (long press, usually), and disconnect the multimedia part?

I'm opening a task for PulseAudio, in case one of the audio developers have an idea about what could be causing this?

[Sergio Callegari (callegar)]

I was also expecting the need of some manual interaction to perform this kind of autoconnection.

I have not compiled anything myself.

- Can it be a problem with the kde bluetooth manager? So there is no problem in ubuntu but you see it in kubuntu?

On the phone, I do not have the option (or I cannot find it) to individually configure the multimedia part.

Thanks for propagating the info.

[Mathieu Trudel-Lapierre (cyphermox)]

Yes, it could be in how the device is configured in kubuntu. What settings can you change from the interface you are using? Anything that is relevant to bluetooth profiles?

[Sergio Callegari (callegar)]

Hi, apparently I cannot change anything on the PC from the user interface to avoid this behavior. But I have found the android menu to prevent the phone from connecting for audio (both phone audio and multimedia audio). With this, I have worked around my immediate problem.

At this point, in my opinion, two less urgent matters remain.

1) There should be a user interface to selectively enable/disable which services are provided to which coupled device. This should be the analogous of what android actually offers. Apparently, this is an issue with the bluez frontends/user interfaces (bluetooth-applet, bluedevil)

2) The system advertises the possibility of connecting for multimedia audio, but in fact cannot route it to the speakers. Apparently this is an issue with the default alsa configuration.

So maybe this bug should be split into two separate bugs for the two points. What do you think?

[Mathieu Trudel-Lapierre (cyphermox)]

Yes, please feel free to file two separate bugs for this, please mark them Wishlist :)

[Konrad Zapałowicz (kzapalowicz)]

This is reported against an old version of Ubuntu and many things has changed since then. Because of that we won't fix this issue however if this behavior repeats on a modern version please fill a bug report against it and we will take it from there.