Missing finalization of avdtp connection

[amorniroli]

Describe the bug

AVDTP connection is never released if it'closed before stream has been established successfully.. To Reproduce

Steps to reproduce the behavior:

Just try this code snippet

uint8_t cid;
bd_addr_t address; // some address

a2dp_sink_establish_stream (address, &cid);
a2dp_sink_disconnect (cid)
a2dp_sink_establish_stream (address, &cid);  // returns ERROR_CODE_COMMAND_DISALLOWED

Expected behavior

The second call to a2dp_sink_establish_stream should return ERROR_CODE_SUCCESS

HCI Packet Logs Not needed

Environment: (please complete the following information):

• btstack branch develop (de13ba803acdb54c41ebfbca4e795757f719a2dd )

Additional context My suggestion for a fix

[mringwal]

Hi Alessandro. How did you run into this?

The main question here should be if it's allowed to call avdtp_disconnect before the event for avdtp_connect() was received in the first place. If yes, we need to make avdtp_connect() more robust, if not an avdtp_connect_abort() would be needed.

Your suggestion might actually work, although I'd rather implement the 'abort' behaviour manually to make sure I didn't miss a case. Let me think about that a bit more.

[mringwal]

Ok, please give 041b66c a try.

[amorniroli]

Hi @mringwal ,

in my scenario, the issue randomly occurred when calling hci_power_control (HCI_POWER_OFF) and a2dp_sink_establish_stream had been already call but still not established.

For example:

• a2dp_sink_establish_stream
• hci_power_control (HCI_POWER_OFF) (sink still not established)
• hci_power_control (HCI_POWER_ON)
• a2dp_sink_establish_stream -> would fail for command disallowed

I'll try the fix in the afternoon, thank you ver much.

[mringwal]

Did you then try to force disconnect by calling a2dp_sink_disconnect, and then run into this?

So, the next question is if/how to trigger avdtp finalize on power off. I would make the argument, that the establish stream request could stay pending and should get executed after the next power on.

[amorniroli]

Did you then try to force disconnect by calling a2dp_sink_disconnect, and then run into this?

Yes, extacly.

in my A2DP_HCI_PACKET_HANDLER, for HCI_STATE_HALTING btstack event I was trying to disconnect the A2DP connection, and then ran into the issue.

I confirm that b8bf1755110d8895952df06fbc69f4ab7788e64d seems to resolve.