[pulseaudio-discuss] [RFCv3 18/20] bluetooth: Call HandsfreeAudioCard.Connect() on non-optional acquire

[João Paulo Rechi Vita]

On Mon, Apr 22, 2013 at 4:43 AM, Mikel Astiz <mikel.astiz.oss at gmail.com> wrote:
> Hi João Paulo,
>
> On Mon, Apr 22, 2013 at 5:07 AM,  <jprvita at gmail.com> wrote:
>> From: João Paulo Rechi Vita <jprvita at openbossa.org>
>>
>> When the HFP sink/source is resumed and the transport is not acquired a
>> new Audio Connection should be started by the HF. This is needed to
>> support audio call transfer from the AG to the HF triggered by the HF.
>> ---
>>  src/modules/bluetooth/bluetooth-util.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/src/modules/bluetooth/bluetooth-util.c b/src/modules/bluetooth/bluetooth-util.c
>> index a00dac7..0fd4c8e 100644
>> --- a/src/modules/bluetooth/bluetooth-util.c
>> +++ b/src/modules/bluetooth/bluetooth-util.c
>> @@ -1873,6 +1873,12 @@ int pa_bluetooth_transport_acquire(pa_bluetooth_transport *t, bool optional, siz
>>          if (t->profile == PROFILE_HFGW) {
>>              struct handsfree_card *hf_card = pa_hashmap_get(t->device->discovery->hf_cards, t->path);
>>
>> +            if (!optional) {
>> +                pa_assert_se(m = dbus_message_new_method_call(t->owner, t->path, "org.ofono.HandsfreeAudioCard", "Connect"));
>> +                pa_assert_se(dbus_connection_send(pa_dbus_connection_get(t->device->discovery->connection), m, NULL));
>> +                return -1;
>> +            }
>> +
>
> I don't see how this improves the problem considering you're supposed
> to block and return the fd, along with imtu and omtu.
>

Sorry, I wrote this a bit late in the evening and didn't make myself
clear enough. The solution to the problem is actually implemented by
this commit plus the previous one. The whole  idea is that when the
sink/source is resumed we do a non-optional acquire, and if that
acquire fails we do not resume it (what makes sense even without
taking this problem into consideration, since there is no stream fd to
be handled). This behavior is implemented in the previous commit.

In this commit we handle the non-optional acquire for (PROFILE_HFGW &&
BLUEZ_VERSION_5), calling Connect() and failing the acquire, since we
can't return a valid stream fd at this point. The Connect() will
trigger an AT+BCC command to the AG and the AG will start an audio
connection establishment that will end up in a call to
NewConnection(), so we'll handle this through the regular
NewConnection() flow.

This idea has worked on my tests, the only drawback is that since
we're not resuming the sink/source right away, the
sink-input/source-output might get moved to the fallback sink/source.
I'm not sure if this is a problem from the client perspective.

Regarding blocking at this point, I think this may not be a good idea
because this is called from I/O thread context.

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