Ubuntu – Bluetooth dongle problem

It was possible to make a patch that makes the dongle work in Linux, but we have some work to do before we get it into the kernel. So the dongle is using a fake CSR chip made by Barrot as previously mentioned. We need to contact the linux kernel maintainers for bluetooth support, but before we do that we need more people than me to confirm that it works. And then I will post our findings here: https://bugzilla.kernel.org/show_bug.cgi?id=60824#c48 and then lastly contact the kernel maintainers (and try to comply with the 'Tips for patch submitters' https://www.kernel.org/doc/linux/MAINTAINERS )

UPDATE 28. december 2020: Since I haven't had time for months to work on a patch for the linux kernel please feel free to post your findings on the bug page mentioned right above and contact the kernel maintainers thereafter if everything goes well.

Please test

Anyone who would like kernel support please test this patch and write back with your results in the comments. I used kernel 5.3. Your kernel may vary in regards to line numbers etc. You might want to check these re. how to check out Ubuntu kernels - unless you use kernels from https://www.kernel.org/:

https://wiki.ubuntu.com/KernelTeam/GitKernelBuild and How/where to clone current 18.04 kernel (5.0.0-37-generic), specifically using Git and https://unix.stackexchange.com/questions/46077/where-to-download-linux-kernel-source-code-of-a-specific-version/46088#46088 and https://stackoverflow.com/questions/8519880/git-checkout-exclude-tags-remotes-from-possibilities-list and https://stackoverflow.com/questions/3404936/show-which-git-tag-you-are-on/3405221#3405221 (I used: git checkout Ubuntu-hwe-5.3.0-28.30_18.04.1) :

diff -Nuar btusb.c_OLD btusb.c
--- btusb.c_OLD 2020-01-29 12:32:30.383536820 +0100
+++ btusb.c 2020-01-29 12:33:49.579840488 +0100
@@ -1599,7 +1599,8 @@
 
    /* Detect controllers which aren't real CSR ones. */
    if (le16_to_cpu(rp->manufacturer) != 10 ||
-       le16_to_cpu(rp->lmp_subver) == 0x0c5c) {
+       le16_to_cpu(rp->lmp_subver) == 0x0c5c ||
+            le16_to_cpu(rp->lmp_subver) == 0x1113) {
        /* Clear the reset quirk since this is not an actual
         * early Bluetooth 1.1 device from CSR.
         */
@@ -3851,7 +3852,7 @@
            set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 
        /* Fake CSR devices with broken commands */
-       if (bcdDevice <= 0x100 || bcdDevice == 0x134)
+       if (bcdDevice <= 0x100 || bcdDevice == 0x134 || bcdDevice == 0x8891)
            hdev->setup = btusb_setup_csr;
 
        set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);

, file is located in the kernel source: drivers/bluetooth

How to determine if you have the same dongle

1. Insert your USB bluetooth dongle into a usb port of your computer.

2. Have two terminal windows open.

3. In the first window please start:

    hcidump
   

Ubuntu: You can install the program via the 'bluez-hcidump' package.

4. In the second window please start:

    sudo hciconfig hci0 down
   
    sudo hciconfig hci0 up
   

Make sure that you enable the bluetooth dongle in your bluetooth manager or you will get an error message e.g.:

Can't init device hci0: Operation not supported (95)

(for those not running with the patch (or incorrect/unsupported dongle))

Can't init device hci0: Operation not possible due to RF-kill (132)

(will likely be shown if your dongle is supported/the patch got applied)

You can install the hciconfig program and obviously need it for bluetooth support Ubuntu: 'bluez' package.

5. Now locate in the first terminal the lines:

    \> HCI Event: Command Complete (0x0e) plen 12
        Read Local Version Information (0x04|0x0001) ncmd 1
   

Make sure you have the same output of hciconfig stated in the top of the question for this event/command.

We e.g. need to know the LMP Subversion and Manufacturer, to be sure that it is the same as the dongle I refer to.

6. Make sure you have the same output of hciconfig stated in the top of the of the question for this event/command:

    \> HCI Event: Command Complete (0x0e) plen 6
    Delete Stored Link Key (0x03|0x0012) ncmd 1
   

, re. status and does it return "Error: Unsupported Feature or Parameter Value". As mentioned above you will only see this message as long as you have not applied the patch.

7. Make sure you have the same output of usb-devices re. your usb bluetooth dongle stated in the top of the question for this command:

    usb-devices | awk '/0a12/' RS=
   

Ubuntu: You need to install package 'usbutils' package to get the program usb-devices.