Bluetooth not working - Cambridge Silicon Radio

I wanted to use Ubuntu Mate once, so today I downloaded version 21.10.
My printers were installed "by itself" and work, very nice.
I have problems only with Bluetooth.


Bus 001 Device 004: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode).

I also get the indicator displayed in the line.

Now when I start the blueman-manager (version 2.2.2) everything looks normal. Now I click on "search" and the following error appears:

Resource Not Ready
Traceback (most recent call last):
File "usr/lib/python3/dist-packages/blueman/bluez/, line 78, in callback
value = proxy.call_finish(result).unpack()
gi.repository.GLib.GError: G-io-error-quark:
GDBus.Error:org.bluez.Error.NotReady: Resource Not Ready (36)

I have uninstalled blueman and bluez and also installed them again.
But without success.

What else can I do?

Thanks Mike

Same issue with me and Cambridge Silicon Radio.

I only see windows drivers.

"Nevertheless, it is difficult to find a Linux-compatible Bluetooth dongle because there aren’t many companies that support Linux. Considering how difficult this task is, we have composed a list of the 5 best USB Bluetooth adapters compatible with Linux."

Good luck, a few years back I had to buy a Bluetooth dongle and I did a lot of research before buying one, as not all support Linux. I ended up buying a Cirago blue-tooth from Amazon because it plainly stated it support Linux. I plugged it in and it worked on more than one Linux OS and more than one brand of computer.

Operating Systems Supported Windows 7, Vista, XP, 2000, Mac OS 10.4.7 or above,Linux

CSR seems to be not a real issue.
I have just checked Ubuntu MATE 21.10 on my:

  • Lenovo SL500 with Broadcom BCM2045B;
  • VAIO F13 with BCM2070;
  • Asus UX32A with Intel 6235.

Here BlueMan can't find neither my Logitech M555b Bluetooth mouse nor Sven Bluetooth speaker. But hcitool scan find them normally:

$ hcitool scan
Scanning ...
 A0:E9:DB:20:FF:FF SVEN PS-100BL
 00:07:61:FD:FF:FF Logitech Bluetooth Mouse M555b

So it is a bug between BlueMan and Bluez. I have reported it as

Other known bluetooth-related bugs:

Need further investigation.


Possible fix is to open View menu and then uncheck Hide unnamed devices. Then click Search to find Bluetooth device to connect, pair and/or trust.
This works normally for my Logitech Bluetooth Mouse M555b:


Hello Norbert,

now I have another problem. When I will start blueman-manager (2.2.2-1), now I dont't have a adapter.

blueman-manager 07.46.14 ERROR    Manager:137 on_dbus_name_appeared: Default adapter not found, trying first available.
blueman-manager 07.46.14 ERROR    Manager:141 on_dbus_name_appeared: No adapter(s) found, exiting

Bus 001 Device 011: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)

sudo systemctl status bluetooth:

bluetooth.service - Bluetooth service
     Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2021-11-15 07:17:02 CET; 38min ago
       Docs: man:bluetoothd(8)
   Main PID: 1005 (bluetoothd)
     Status: "Running"
      Tasks: 1 (limit: 9325)
     Memory: 1.8M
        CPU: 70ms
     CGroup: /system.slice/bluetooth.service
             └─1005 /usr/lib/bluetooth/bluetoothd

What I'm missing now?
Thanks Mike

What do you have for rfkill list , hcitool dev and hcitool scan ?

rfkill list

4 bluetooth hci0   unblocked unblocked

hcitool dev


hcitool scan

Device is not available: No such device

Have you considered trying a Bluetooth dongle? Personally, I can recommend the Hideez Bluetooth dongle. It works flawlessly out of the box with Linux, and I haven't experienced any connectivity issues. It's also compatible with Windows and macOS computers, if you ever need to switch.

You can check it out on Amazon here:

I had good experience with the ASUS BT-400, you can find it on Amazon for $10.