bluetooth A2DP needs Reconnection to work

[Antoine GRÉA]

While trying to pair and use my headset I always run in the same problem. The pairing works but upon connection the sound does not get streamed to the headset.
For me the default selected profile is A2DP but sound test doesn't work. When I reconnect as is it still doesn't work. On switching mode to HSP/HFP the headset works as intended (mono with mic). If then switching to A2DP the device gets unselected in the swithboard interface and the panel seems broken from it.
There the minimal fix I found so far is to proceed as this : connect the headset, switch to HSP, reconnect the device, switch to A2DP.

I have the following dmesg output :
```
[ 436.534749] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 436.534752] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 436.534753] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 436.544750] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 436.544753] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 441.186504] Bluetooth: hci0 SCO packet for unknown connection handle 257
[ 441.186508] Bluetooth: hci0 SCO packet for unknown connection handle 257
[ 441.186510] Bluetooth: hci0 SCO packet for unknown connection handle 257
[ 443.120211] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 443.130214] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 443.130219] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 443.130220] Bluetooth: hci0 SCO packet for unknown connection handle 0
[ 443.218566] input: 00:18:09:16:5A:17 as /devices/virtual/input/input19
[ 447.831147] Bluetooth: hci0 SCO packet for unknown connection handle 257
[ 447.831151] Bluetooth: hci0 SCO packet for unknown connection handle 257
[ 447.831152] Bluetooth: hci0 SCO packet for unknown connection handle 257
```

I found a similar bug on ubuntu and upstream for pulseaudio and bluez : https://bugs.launchpad.net/ubuntu/+source/bluez/+bug/1438510

I am filing it here too because of the issue caused in the UI of switchboard.

[Danielle Foré (danrabbit)]

A2DP has been fixed in a newer version of PulseAudio. There's unfortunately nothing we can do in Switchboard to address this issue.

Marking invalid, because there's no work item for us

[Antoine GRÉA (grea09)]

I think that it may be good to handle errors from pulseaudio in the user interface so that incoherent behaviour don't affect user experience too much. For exemple when the profile change fails the UI must either report the error or remove the faulty profile or revert to the current profile.
I attach a screenshot of what I mean by that.