I bought a CSR 4.0 bluetooth toogle hopping to use for music and stuff. I have already tried a plug n' play BT toogle but I can't remember its brand or model (it was white though). It worked for 4.0 devices but not for my 5.0 headphone for instance.
When I did the same thing for this "plug n' play" usb toogle it didn't work. After search the web and countless forums I come here again asking for help. Here is a quick list of thinks I tried and some details of the issue:
First I installed the bluez and blueman packages (through synaptic) both in dev versions as well. When I open it and try to pair with my phone, it keeps searching endlessly.
Also while blueman tries to search, the bluetooth system tool does as well.
However, after installing the packages, my desktop is recognizable by my phone. But when I try to pair them: an error mensage apears.
That was pretty much what I did to solve it. The rest was me trying to diagnose the problem. It follows:
$ dmesg | grep Bluetooth
[ 26.575777] Bluetooth: Core ver 2.22
[ 26.575801] Bluetooth: HCI device and connection manager initialized
[ 26.575806] Bluetooth: HCI socket layer initialized
[ 26.575809] Bluetooth: L2CAP socket layer initialized
[ 26.575812] Bluetooth: SCO socket layer initialized
[ 27.131101] Bluetooth: hci0: CSR: Unbranded CSR clone detected; adding workarounds...
[ 50.842293] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 50.842294] Bluetooth: BNEP filters: protocol multicast
[ 50.842302] Bluetooth: BNEP socket layer initialized
[ 108.698627] Bluetooth: RFCOMM TTY layer initialized
[ 108.698636] Bluetooth: RFCOMM socket layer initialized
[ 108.698643] Bluetooth: RFCOMM ver 1.11
[ 275.396684] Bluetooth: hci0: command 0x0c3a tx timeout
...
[ 847.972771] Bluetooth: hci0: command 0x0401 tx timeout
[ 1135.777423] Bluetooth: hci0: command 0x0c14 tx timeout
[ 1596.128411] Bluetooth: hci0: CSR: Unbranded CSR clone detected; adding workarounds...
[ 1614.944973] Bluetooth: hci0: command 0x0401 tx timeout
...
[ 8563.066095] Bluetooth: hci0: command 0x0401 tx timeout
[ 9612.606636] Bluetooth: hci0: CSR: Unbranded CSR clone detected; adding workarounds...
[ 9632.069367] Bluetooth: hci0: command 0x0401 tx timeout
[ 9644.069487] Bluetooth: hci0: command 0x0401 tx timeout
[ 9656.073641] Bluetooth: hci0: command 0x0401 tx timeout
[ 9668.069734] Bluetooth: hci0: command 0x0401 tx timeout
[ 9680.069856] Bluetooth: hci0: command 0x0401 tx timeout
[ 9692.069981] Bluetooth: hci0: command 0x0401 tx timeout
[ 9704.074094] Bluetooth: hci0: command 0x0401 tx timeout
[ 9716.070247] Bluetooth: hci0: command 0x0401 tx timeout
[ 9728.070347] Bluetooth: hci0: command 0x0401 tx timeout
[ 9740.070431] Bluetooth: hci0: command 0x0401 tx timeout
And:
$ lsusb | grep Cambridge
Bus 001 Device 005: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
$ hciconfig
hci0: Type: Primary Bus: USB
BD Address: 00:1A:7D:DA:71:10 ACL MTU: 640:4 SCO MTU: 64:8
UP RUNNING PSCAN ISCAN
RX bytes:778 acl:0 sco:0 events:61 errors:0
TX bytes:4789 acl:0 sco:0 commands:591 errors:540
Finally I saw that tip in one askubuntu topic and tried my own. The result:
$ sudo hcidump
HCI sniffer - Bluetooth packet analyzer ver 5.53
device: hci0 snap_len: 1500 filter: 0xffffffffffffffff
< HCI Command: Inquiry (0x01|0x0001) plen 5
lap 0x9e8b33 len 8 num 0
< HCI Command: Reset (0x03|0x0003) plen 0
As a result of the code from another terminal tab
$ sudo hciconfig hci0 down
$ sudo hciconfig hci0 up
Can't init device hci0: Connection timed out (110)
So long I've seen, $ sudo hciconfig hci0 reset also works. Then the bluetooth system manager and gnome control panel behave like this and I have to remove and insert the device to be connected again.
Finally, I read that this could happen as the kernel were updated from Ubuntu 16 to 20. Mine is 5.8.0-43-generic, but people complain about this problem since 5.4. I'm not sure if installing an old kernel would solve it once I know almost nothing about it.
Any help is welcome ;)