[pulseaudio-discuss] bluetooth headset audio not supported by ofono

[Arun Raghavan]

On 4 February 2015 at 14:10, David Henningsson
<david.henningsson at canonical.com> wrote:
>
>
> On 2015-02-03 15:04, Tanu Kaskinen wrote:
>>
>> On Mon, 2015-02-02 at 16:49 +0100, Georg Chini wrote:
>>>
>>> I think the release notes for 6.0 should be revised to account for
>>> that.
>>
>>
>> Indeed. Before I update the notes, though, I want to get a decision on
>> whether we will release with your patch to use both backends
>> side-by-side (probably implies another rc before final release), or will
>> we postpone that to the next release. Either is fine by me, but I'd vote
>> for releasing with your patch.
>
>
> Hmm. I'm not totally sure about the differences between HF and AG so take
> this with a grain of salt, but...
>
> It seems to me that it's not extremely unlikely that either of us will step
> into the other domain in the future, i e, bluez 5 might implement AG audio
> or PulseAudio might implement a native support for HF.
>
> Also, if the AG plugin of Bluez 5 supports RFCOMM/AT commands then we're
> already partially overlapping, because that's what we use to set/get headset
> volume and mic gain. If we enable both backends, will that then send AT
> commands from both backends when we try to set the volume, or...?
>
> Hence, instead of removing all backend switching code, maybe we should
> instead add a switching mode "both" which does what you say. Or potentially
> replace "auto" with "both", if "auto" now makes no sense.
>
> Finally, I remember Arun had a strong preference for not enabling the ofono
> backend by default, so Arun, could you elaborate upon whether that still
> makes sense given this new information?

The reason I was against a "both" mode is that it seems odd to me from
a system integration perspective. The current situation seems to be
either you have oFono as a part of your system and you're using it for
modem management, some amount of BT audio management, and so forth.
Else, you're using PulseAudio for the BT audio management (the stuff
that BlueZ used to do but dropped in 5.x).

It seems odd to me to have a "both" mode -- I'd like to add back the
features we supported before the BlueZ 5.x migration caused us to
regress. Once Wim's HSP work is out, that basically leaves the HF role
(PA on your acting as a headset). If I understand correctly, that will
overlap with oFono (if oFono wasn't bringing a telephony stack along
with it, I wouldn't be objecting to just using it as our external dep
that provides these features)..

So to my mind, having a both mode does not seem too useful from a
system integration point of view -- either we have oFono provide these
and other services, system-wide, or we're having PA manage whatever
(sub?)set of features we want to.

Cheers,
Arun