Problems with ASoC and Bluetooth routing

[Carl Lobo]

It's a shame about the volume. I'm no specialist but is it possible
that there's some kind of coupling problem between the BT chip and the
wm8753. That may also explain the workaround required - disconnecting
and reconnecting the muxer the first time.
The mixer news isn't too good either, because we could support
changing mixer settings when the headset volume control with the
bluez4 API I think. :(
My Jawbone2 still isn't working, as in it sounds like there's
something coming in - feedback from the buttons gets played back in a
very distorted way. Angus Ainslie said on the community list that no
format conversion takes place inside the wm8753 chip. So maybe because
the analog signal coming from the GSM isn't in a compatible format
with the headset. It has no A2DP profile support it only supports HFP.
So maybe the output from the modem isn't in a format compatible with
HFP codecs (or maybe mine doesn't support all of them)?