After replace /usr/lib/kernel-overlays/base/lib/modules/4.9.113/kernel/drivers/bluetooth/btrtl.ko. We need to disable built-in bluetooth and active usb dongle.We can vi /storage/.config/autostart.sh , add these lines:
rfkill list |grep `hciconfig -a |grep UART|cut -f1 -d:`|cut -f1 -d:|xargs -n1 rfkill block
systemctl restart bluetooth.service
Let’s review information about rtl8761b:
CoreELEC:~ # hciconfig -a
hci0: Type: Primary Bus: USB
BD Address: xx:xx:xx:xx:xx:xx ACL MTU: 1021:5 SCO MTU: 255:11
UP RUNNING PSCAN
RX bytes:77530663 acl:129616 sco:0 events:2347 errors:0
TX bytes:80981 acl:2069 sco:0 commands:225 errors:0
Features: 0xff 0xff 0xff 0xfe 0xdb 0xfd 0x7b 0x87
Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
Link policy: RSWITCH HOLD SNIFF PARK
Link mode: SLAVE ACCEPT
Name: 'CoreELEC #1'
Class: 0x0c0000
Service Classes: Rendering, Capturing
Device Class: Miscellaneous,
HCI Version: 5.1 (0xa) Revision: 0xd99
LMP Version: 5.1 (0xa) Subversion: 0x646b
Manufacturer: Realtek Semiconductor Corporation (93)
CoreELEC:~ # lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 0bda:8771 Realtek Semiconductor Corp. Bluetooth Radio
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
CoreELEC:~ # lsusb -s 001:002 -v
Bus 001 Device 002: ID 0bda:8771 Realtek Semiconductor Corp. Bluetooth Radio
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 224 Wireless
bDeviceSubClass 1 Radio Frequency
bDeviceProtocol 1 Bluetooth
bMaxPacketSize0 64
idVendor 0x0bda Realtek Semiconductor Corp.
idProduct 0x8771
bcdDevice 2.00
iManufacturer 1 Realtek
iProduct 2 Bluetooth Radio
iSerial 3 00E04C239987
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x00b1
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 500mA
...