[pulseaudio-discuss] [RESEND] [PATCH v3 1/2] bluetooth: Add support for automatic switch between hsp and a2dp profiles

[Arun Raghavan]

On 2 February 2016 at 14:39, Pali Rohár <pali.rohar at gmail.com> wrote:
> On Tuesday 02 February 2016 14:24:07 Arun Raghavan wrote:
>> > > > @@ -35,16 +35,18 @@
>> > > >
>> > > >  #include "module-bluetooth-policy-symdef.h"
>> > > >
>> > > > -PA_MODULE_AUTHOR("Frédéric Dalleau");
>> > > > -PA_MODULE_DESCRIPTION("When a bluetooth sink or source is added,
>> > > > load module-loopback");
>> > > > +PA_MODULE_AUTHOR("Frédéric Dalleau, Pali Rohár");
>> > > > +PA_MODULE_DESCRIPTION("Automatically switch between bluetooth
>> > > > hsp
>> > > > and a2dp profiles and automatically load module-loopback when a
>> > > > bluetooth sink (ag) or source (ag, a2dp_source) is added");
>> > >
>> > > I'd just rewrite this to be "Policy module to make using bluetooth
>> > > devices out-of-the-box easier".
>> >
>> > Personally I'm fine with both descriptions so its up to other
>> > pulseaudio
>> > reviewers/maintainers.
>>
>> I prefer the shorter name in the description, so let's go with that.
>
> Ok.
>
>> > > >  PA_MODULE_VERSION(PACKAGE_VERSION);
>> > > >  PA_MODULE_LOAD_ONCE(true);
>> > > >  PA_MODULE_USAGE(
>> > > > +        "switch=<Switch between hsp and a2dp profile?> "
>> > >
>> > > Maybe call this "autoswitch".
>> >
>> > "autoswitch" or "auto_switch"?
>>
>> I'm not a huge fan of the underscores in our modarg names, but I'm fine
>> with either.
>
> Ok.
>
>> > > > +    /* Flag this card for revert */
>> > > > +    pa_proplist_sets(new_data->proplist, "bluez-revert",
>> > > > "true");
>> > > > +    return PA_HOOK_OK;
>> > >
>> > > What is the reasoning behind having this property?
>> >
>> > For each card I need to know if card needs to be "reverted" in
>> > future.
>>
>> Is this for a case where a device is manually kept in the hsp profile
>> and you don't want to touch that?
>
> Yes. When user chose manually to use hsp profile.
>
>> > > In general, I prefer the module doing its book-keeping locally
>> > > rather
>> > > than (ab)using the proplist for state.
>> >
>> > Ok, what to use then? How to store for each private boolean flag
>> > needed
>> > just by this module?
>>
>> Usually you'd do something like have a hashmap in the module's
>> userdata, and then you could add your pa_card to that hashmap if it
>> needs a revert (and remove when you're done with the revert). The
>> userdata is available in all the hook callbacks.
>
> But then I need to deal with removing card (e.g. somebody unplug usb
> bluetooth adapter when voice call via hsp profile is active)... And
> maybe other scenarios?

Yes. You just need to use PA_CORE_HOOK_CARD_UNLINK.

-- Arun