Media API with more than one headset

[Peter Kornatowski <pkorn@xxxxxxx>]

Hi,

I'm using the new bluez media api to set bluetooth headsets into 
playing mode and get the fd's of the corresponding sockets with a 
program written in C. This works fine with just one headset, but I'm 
using up to three at the same time over three bluetooth adapters. So 
my program (bt-audio) creates a dbus-service with three paths 
(/test/endpoint0, ...1, ...2) and each path has an interface 
org.bluez.MediaEndpoint with the four needed methods 
(SetConfiguration etc.). Then it scans for turned on headsets and 
calls RegisterEndpoint on the appropriate adapter-path. Then bluez 
calls three times SetConfiguration on my service. So basically like 
in the python-example "simple-endpoint". After that my app calls 
three times Acquire with "rw" on each of the given transport-paths to 
receive the socket-fd's.
As I said, this works well and I can play and record some raw-files 
with very good quality. But when one of the headsets is turned off, 
the other two are put out of playing-mode. When I retry to put them 
back in playing-mode by calling UnregisterEndpoint and then 
RegisterEndpoint again, I just get 
"GDBus.Error:org.bluez.Error.NotAuthorized: Operation Not Authorized" 
and see "sco_bind: Address already in use" in syslog. When retrying 
too often, bluetoothd segfaults (but this may be related to the way i 
tried some recovery of this problem in my code) with:
kernel: [34309.873606] bluetoothd[29235]: segfault at 6e652f74 ip 
b76b9b20 sp bf93c430 error 4 in bluetoothd[b768c000+7e000]

Only after restarting my program (and thus re-registering my 
dbus-service), I am able to put the headsets back in playing mode again.

I also tried this use-case with your simple-endpoint python-script by 
modifying it like this:

def acquire_cb(fd, imtu, omtu):
	print "Acquire successfull! New fd: %s with iMTU %i and oMTU %i" % 
(fd, imtu, omtu)
def acquire_error(error):
	print "Acquire failed: %s" % (error)
	mainloop.quit()

...

@dbus.service.method("org.bluez.MediaEndpoint", in_signature="oay", 
out_signature="")
def SetConfiguration(self, transport, config):
	print "SetConfiguration (%s, %s)" % (transport, config)
	media_transport = dbus.Interface(bus.get_object("org.bluez", 
transport), "org.bluez.MediaTransport")
	media_transport.Acquire("rw", reply_handler=acquire_cb, 
error_handler=acquire_error)
	return

So even after starting two or three processes of this script (each 
with a different hciX), I get the same behaviour: putting all 
headsets in playing mode is no problem, but turning off one headset 
puts the others out of playing mode. Trying to put them back in 
playing mode requires a restart of the scripts, otherwise I just get 
the same error: "Acquire failed: org.bluez.Error.NotAuthorized: 
Operation Not Authorized".

So why are the other headsets always put out of playing mode and why 
can't you put them back in playing mode again? Looks like a bug to 
me, hopefully someone of you can help. I attached the syslog cutout 
of this problem, too (first section is with my C-program, second with 
the python-script).

Thanks,
Peter

Attachment: media_api_hs_disconnect.log
Description: Binary data