My patch to fix hci0: Opcode 0x c77 failed: -56 issue from kernel log and No default controller available in bluetoothctl. Stuttering audio in bluetooth device will also be fixed (in my case) probably because the kernel is using generic driver as fallback.

Applying patch

The patch is simply adding the hardware ID and manufacturer of the bluetooth device to usb device table in btusb.c. For alternative way check this branch

1. Update code to current kernel version and Get the ID

$ ./update.sh
$ lsusb | grep tooth
Bus 002 Device 003: ID 13d3:3537 IMC Networks Bluetooth Radio

2. stage the changes with $ git add . so next diff from git will only show the custom patch

3. Edit the source code

static const struct usb_device_id blacklist_table[] = {
  ...

	/* Additional Realtek 8822BE Bluetooth devices */
	{ USB_DEVICE(0x13d3, 0x3526), .driver_info = BTUSB_REALTEK },
+	{ USB_DEVICE(0x13d3, 0x3537), .driver_info = BTUSB_REALTEK },
	{ USB_DEVICE(0x0b05, 0x185c), .driver_info = BTUSB_REALTEK },

  ...
}

4. Generate the patch with

git diff > btusb.patch

5. Apply patch with

patch < btusb.patch

6. Install module manually

sudo make install

or using dkms (will automatically rebuild when updating kernel)

sudo make dkms-install

Uninstalling

sudo make uninstall

References

• https://askubuntu.com/questions/791584/bluetooth-not-working-in-ubuntu-16-04-with-0cf33004-atheros-adapter
• https://gist.github.com/hwchong/8738e100ec4e140bae2cac2894c29d65