Hello,

 

I have been experimenting with the bluetooth audio on my tinkerboard.  The issue is both present on the last rockchip-next (4.1x I think) and the rockchip-current 5.8.18 kernel. I am using bluez and bluealsa.

 

The problem is specific to the onboard bluetooth, using an external bluetooth dongle (a cheap and old CSR Bluetooth 3.0 dongle from China)  works as expected, I can even send audio to multiple devices simultaneously (quality is very bad, but thats a bandwidth problem).

 

As long as I just connect one bluetooth audio device everything is fine.  I can have multiple paired, but disconnected, devices and as long as I connect and play and diconnect, things keep working.  But as soon as I try to connect a second device, while another one is already connected (not even playing), the second device shortly shows up as connected in `bluetoothctl` (while the LED on the speaker itself stil shows not-connected) and about 10-20 seconds later the device shows up as disconnected and would not even reconnect unless switched on or off.  

 

The error logged by bluetoothd / bluez (5.55-1) is

bluetoothd[15142]: profiles/audio/avdtp.c:avdtp_connect_cb() connect to 74:A3:xx:xx:xx:xx: Connection refused (111)

 

The connection process does not reach the bluealsa layer, I had similar problems when quickly testing with pulseaudio's bluetooth module.

 

My question:

Is there anywhere in the armbian tinkerboard configuration some hardcoded option to only connect to one device at a time?  I cannot imagine this to be alimit of the on-board chip, Are there any config options for the HCI UART kernel driver?

Providing logs with 

armbianmonitor -u

 helps with troubleshooting and significantly raises chances that issue gets addressed.