Wrong /var/lib/bluetooth/<BD address>/config prevents setting correct hci class

[Jerzy Luszawski]

Binary package hint: bluez-utils

When entry 'class' exists in /var/lib/bluetooth/<BD address>/config it takes precedence over class settings in /etc/bluetooth/hcid.conf. When starting/restarting bluetooth, regardless of changes in /etc/bluetooth/hcid.conf hci class remains as saved in /var/lib/bluetooth/<BD address>/config.

I discovered it when trying to install the newest version of bluez-utils (3.19). It has "class 0x000100;" set in the default hcid.conf. After installation hciconfig -a showed:
        Class: 0x000100
        Service Classes: Unspecified
        Device Class: Computer, Uncategorized
 I adjusted the "class" entry in etc/bluetooth/hcid.conf and restarted bluetooth services, but nothing changed. I spent some time on it, and gave up, reverting to my old version of bluez-utils, which are in ubuntu feisty repository (3.9). Then i found out, that the problem persists, and I had no services on the device available!
I found out that removing the file /var/lib/bluetooth/<BD address>/config resolves the problem, as new file is created with no class entry, and data from /etc/bluetooth/hcid.conf are processed.

Steps to recreate the condition:
-----------------------------------------------------------------------------------------------
root@jl-desktop:~# cat /var/lib/bluetooth/00\:08\:1B\:02\:3B\:67/config
mode discoverable

(this is the only line in my properly working file)

root@jl-desktop:~# hciconfig -a
hci0: Type: USB
        BD Address: 00:08:1B:02:3B:67 ACL MTU: 192:8 SCO MTU: 64:8
        UP RUNNING PSCAN ISCAN
        RX bytes:2750 acl:0 sco:0 events:57 errors:0
        TX bytes:1210 acl:0 sco:0 commands:56 errors:0
        Features: 0xff 0xff 0x0f 0x00 0x00 0x00 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
        Link policy: HOLD SNIFF PARK
        Link mode: ACCEPT MASTER
        Name: 'JL-DESKTOP_(0)'
        Class: 0x3e0104
        Service Classes: Networking, Rendering, Capturing, Object Transfer, Audio
        Device Class: Computer, Desktop workstation
        HCI Ver: 1.1 (0x1) HCI Rev: 0x33d LMP Ver: 1.1 (0x1) LMP Subver: 0x33d
        Manufacturer: Cambridge Silicon Radio (10)

root@jl-desktop:~# echo class 0x000100 >> /var/lib/bluetooth/00\:08\:1B\:02\:3B\:67/config
root@jl-desktop:~# /etc/init.d/bluetooth restart
 * Restarting Bluetooth services [ OK ]
root@jl-desktop:~# hciconfig -a
hci0: Type: USB
        BD Address: 00:08:1B:02:3B:67 ACL MTU: 192:8 SCO MTU: 64:8
        UP RUNNING PSCAN ISCAN
        RX bytes:3344 acl:0 sco:0 events:68 errors:0
        TX bytes:1502 acl:0 sco:0 commands:67 errors:0
        Features: 0xff 0xff 0x0f 0x00 0x00 0x00 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
        Link policy: HOLD SNIFF PARK
        Link mode: ACCEPT MASTER
        Name: 'JL-DESKTOP_(0)'
        Class: 0x000100
        Service Classes: Unspecified
        Device Class: Computer, Uncategorized
        HCI Ver: 1.1 (0x1) HCI Rev: 0x33d LMP Ver: 1.1 (0x1) LMP Subver: 0x33d
        Manufacturer: Cambridge Silicon Radio (10)

root@jl-desktop:~# gedit /var/lib/bluetooth/00\:08\:1B\:02\:3B\:67/config
(I manually deleted the previously inserted line with class 0x000100)
root@jl-desktop:~# /etc/init.d/bluetooth restart
 * Restarting Bluetooth services [ OK ]
root@jl-desktop:~# hciconfig -a
hci0: Type: USB
        BD Address: 00:08:1B:02:3B:67 ACL MTU: 192:8 SCO MTU: 64:8
        UP RUNNING PSCAN ISCAN
        RX bytes:3938 acl:0 sco:0 events:79 errors:0
        TX bytes:1794 acl:0 sco:0 commands:78 errors:0
        Features: 0xff 0xff 0x0f 0x00 0x00 0x00 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
        Link policy: HOLD SNIFF PARK
        Link mode: ACCEPT MASTER
        Name: 'JL-DESKTOP_(0)'
        Class: 0x3e0104
        Service Classes: Networking, Rendering, Capturing, Object Transfer, Audio
        Device Class: Computer, Desktop workstation
        HCI Ver: 1.1 (0x1) HCI Rev: 0x33d LMP Ver: 1.1 (0x1) LMP Subver: 0x33d
        Manufacturer: Cambridge Silicon Radio (10)
---------------------------------------------------------------------

I could not find any references to /var/lib/bluetooth/<BD address>/config, and tracking it down took me some time, so I file this as a bug.

[Marcel Holtmann (holtmann)]

Don't touch hcid.conf at all. The values from the /var/lib/bluetooth wll overwrite any settings done in hcid.conf and this is on purpose. If you wanna change your class of device, use the D-Bus methods or bluetooth-properties.

[Jerzy Luszawski (dr-agon)]

Tanks for the explanation.
I have bluetooth working OK. I was just surprised, that after installing the new bluez-utils version my device reported no available services, and it was before I started to play with any configuration files. All I wanted was my configuration to remain as with earlier version, and it seemed that it was spoiled by installing new version.

[Marcel Holtmann (holtmann)]

It has been like this for a while. Even in Feisty. With the new version we know enforce using D-Bus more and slowly reduce the importance and need of hcid.conf.

[Jerzy Luszawski (dr-agon)]

After the explanation it seems the problem doesn't matter any more. To clean up, I change the status to invalid.