2009-04-06 23:26:49

by Brock Denson

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Subject: headset - sco times out after 1 minute

I am having some trouble with SCO. I can connect to a headset and start
SCO, but after about 1 minute the SCO stops, but remains connected.

I know very little about Dbus or the inner workings of Bluetooth.

Some hopefully useful information:
BlueZ versions tried 4.30 and 4.34 with ./configure as per README,
latest version from git using bootstrap-configure
Linux Distribution Fedora Core 10
Kernel version

Steps to recreate:
1. Attach USB Bluetooth device
2. Download pskeys
Bccmd psload -r pskeys.psr
3. Get default adapter
Dbus-send --system --print-reply --type=method_call
--dest=org.bluez / org.bluez.Manager.DefaultAdapter
4. Create a device
Dbus-send --system --print-reply --type=method_call
--dest=org.bluez /org/bluez/2030/hci0 org.bluez.Adapter.CreateDevice
5. Connect to device
Dbus-send --system --print-reply --type=method_call
--dest=org.bluez /org/bluez/2030/hci0/dev_11_11_11_11_11_11
6. Start SCO
Dbus-send --system --print-reply --type=method_call
--dest=org.bluez /org/bluez/2030/hci0/dev_11_11_11_11_11_11

The final dbus-send command returns an error after about 30
(suspiciously close to DEFAULT_DEFER_TIMEOUT in common/btio.c:48)
seconds of org.freedesktop.DBus.Error.NoReply and the SCO stops about 30
seconds later. I have looked around a good bit, but have had trouble
finding documentation on the bluez 4.x branch.
The error from bluetoothd -n -d indicates a G_IO_ERR at the time the SCO
stops (~1 minute) from connect_cb() in common/btio.c:124 which then
calls sco_connect_cb() in audio/headset.c:544
I do not see any errors in the kernel log, and have tried to capture the
dbus traffic with dbus-monitor (which is also a bit short on docs as
well) with little luck. I have tried things like:
Dbus-monitor --system
Dbus-monitor --system "type='method_call'"
Dbus-monitor --system "type='method_call',interface='org.bluez.Headset'"

I would love to figure that out as well, by the way.

I would appreciate any help here,

Brock Denson | Sr. Applications Engineer | m. 972 900-6806 | o. 214