[pulseaudio-discuss] Failure to connect Sony headsets

[João Paulo Rechi Vita]

Hello,

On Tue, Jun 26, 2018 at 3:55 AM, Luiz Augusto von Dentz
<luiz.dentz at gmail.com> wrote:
> Hi Joao,
>
> On Thu, Jun 21, 2018 at 10:21 PM, João Paulo Rechi Vita
> <jprvita at gmail.com> wrote:
>>
>> I'm adding some extra debug around the initial profile selection to
>> have a clear picture of what is going on there and will keep analyzing
>> this further. I'll get back when I have something, now that I have a
>> better idea of what to look for, but any insights are welcome in the
>> meantime.
>
> Just a heads up Ive sent a patch for BlueZ that shoud fix this for
> MW600, it turns out the device did not reconnect A2DP after HFP and
> would only do that is SCO is connected which is too late.

That is great news, although I don't see any new patch on the list.
Can you share a link?

Just to add more info (although it may not be super useful at this
point), on the past few days I've been experimenting with how
module-card-restore is affecting this problem, combined with
increasing WAIT_FOR_PROFILES_TIMEOUT_USEC to 60s and got the following
summary:

WAIT_FOR_PROFILES_TIMEOUT_USEC=60s, module-card-restore restores A2DP:
a2dp_sink available: Yes, headset_head_unit available: Yes, active
profile: a2dp_sink
WAIT_FOR_PROFILES_TIMEOUT_USEC=60s, module-card-restore restores HSP:
a2dp_sink available: No, headset_head_unit available: Yes, active
profile: headset_head_unit
WAIT_FOR_PROFILES_TIMEOUT_USEC=3s, module-card-restore restores HSP:
a2dp_sink available: No, headset_head_unit available: No, active
profile: None -- card removed
WAIT_FOR_PROFILES_TIMEOUT_USEC=3s, no module-card-restore: a2dp_sink
available: No, headset_head_unit available: No, active profile: None
-- card removed
WAIT_FOR_PROFILES_TIMEOUT_USEC=3s, module-card-restore tries to
restore a2dp_sink but it does not because it is not available:
a2dp_sink available: No, headset_head_unit available: No, active
profile: None, card removed
WAIT_FOR_PROFILES_TIMEOUT_USEC=3s, module-card-restore restores A2DP
(this is without the patch that makes m-c-r ignore unavailble
profiles, just for testing): a2dp_sink available: Yes,
headset_head_unit available: Yes, active profile: off

Also, I've tried to make module-bluez5-device avoid acquiring the
transport right away when the card is created and have the source/sink
be created suspended, deferring the audio connection establishment to
when there is an actual stream to be transferred (which should resume
the sink) or we get an incoming connection. But I looks like I have
messed up the state machine while doing that and the source/sink was
never resumed, which is not really useful. I going to try your BlueZ
fix first (when I find it), and after that we can see if there is
anything else that needs to be fixed in PulseAudio.

> Anyway I
> briefly discussed with Tanu about the ordering of initial profile
> shall be bluetooth-policy first than restore since that means restore
> is run last overriding any profile set by bluetooth-policy in case the
> user has set anything as preference.
>

In my tests module-bluetooth-policy was not affecting this problem at
all since it was not taking any actions on these profiles (and I
didn't have any media.role=phone stream active). Are you trying to
address a different problem with that change?

My initial thought is that module-card-restore does more harm then
good for UX with Bluetooth headsets, actually. It sure was useful when
module-bluetooth-policy did not exist, but I think a good user
experience is based on dynamically adapting according to which streams
are active at a certain moment, instead of user input. This is mostly
covered by module-bluetooth-policy + module-role-{cork,ducking}, but I
don't think anything switches the profile to A2DP when there is a
"high-quality" stream playing if module-card-restore initially set the
profile to headset_head_sink. Maybe this is more of a UI bug and a
user-focused UI should not expose means for the user to manually
select the profile, which is aligned with a previous comment from
Tanu:

> On Thu, Jun 14, 2018 at 4:57 AM, Tanu Kaskinen <tanuk at iki.fi> wrote:
>
> If module-bluetooth-policy is sufficient, then module-card-restore
> won't do anything anyway, because you never set the profile manually.
> If you ever set the profile manually, that's an indication that module-
> bluetooth-policy isn't always good enough.

Still, I think the general user will only manually change the profile
either if things go wrong for some reason, or before PulseAudio 12,
because HSP/HFP was selected by default. If they leave the setting on
the "wrong profile", it affects their experience next time using the
headset, despite if it is right afterwards or months later, or if the
headset has been removed and paired with a different machine in the
meantime. Again, it may be a UI issue after all, but comparing to
Android/iPhone (which is what a lot of users are likely to have
previous experience with), there is not even a way for users to
manually set the active profile for headsets. They can enable/disable
a profile for an specific headset on Android tho, which gives them
some sort of control. I don't think there is any client API for
disabling profiles on cards, but maybe that could be a good
alternative?

I realized automatic audio routing is a hot-topic and I may be missing
some alternatives or other previous discussions -- please point me to
them if that is the case.

--
João Paulo Rechi Vita
http://about.me/jprvita