Some headsets appear don't work when BlueZ connecting with both HSP AG and HFP AG.

Hi linux-bluetooth,


PipeWire recently got HFP AG support,

its native headset backend registers both HSP AG profile and HFP AG profile with `AutoConnect` enabled by default.

Hence, BlueZ would trying to connect headset with both HSP and HFP. Seems it causes some headsets stop to work with HFP/HSP profile.

Discussions on PipeWire: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/604#note_773590

Frédéric Danis says:

Currently it seems to me that there are at least 3 behaviours when both native HSP and HFP are enabled, depending on the Headset/Speaker:

   with Sony WH-1000XM3, iiuc:
       HFP is tried first, starting SLC process
       then a connection to HSP is rejected by the headset which stops to send AT commands on the HFP RFComm channel
       Audio is not working
   with Sony WH-CH710N:
       HFP is tried first, starting SLC process
       then a connection to HSP is rejected by the headset, but the headset keeps on sending AT commands on the HFP RFComm channel
       Audio is working
   with JBL GO 2 speaker:
       HFP is tried first, starting SLC process on a RFComm channel
       then HSP is connected on a second RFComm channel and following HFP AT commands are sent on this second channel
       Audio is not working (iirc)

Can it be fixed in BlueZ? For example, do not auto-connect HSP or HFP profile if the other one has been connected. Maybe to add an extra option "Conflicts" on "org.bluez.ProfileManager1.RegisterProfile()" to indicate UUIDs which conflict with registered profile.

Regards,
Bao