Re: choosing SCO parameters at run time

[Marcel Holtmann <marcel@holtmann.org>]

Hi Johan,

> > I have a question related to SCO packet path configuration for
> > Bluetooth HSP/HFP profiles. As I understand,
> > we need to use SCO routing option in etc/bluetooth/audio.conf to
> > select the voice path to be over HCI or PCM.
> > It seems the option is configured at the init time.Can I select PCM or
> > HCI routing at runtime?
> 
> That variable isn't intended to trigger a SCO routing change but to
> simply tell BlueZ & Pulse Audio (or whatever audio subsystem you use)
> what the hardware platforms configuration is. I.e. the actual routing of
> your bluetooth controller needs to be configured separately (and afaik
> there's no standard HCI command through which it could be done which
> further promotes the idea that BlueZ shouldn't have any code for it).

in theory this is possible and I know of a few chips that can change the
routing before establishing the SCO link. However this is all highly
vendor specific and needs extensive kernel and driver support.

So while possible, I haven't seen it in practice at all. Especially with
modern chips supports more than one SCO over PCM.

Regards

Marcel