[pulseaudio-discuss] card: Only set active_profile with available profile

[Tanu Kaskinen]

On Sun, 2013-11-17 at 17:53 +0200, Luiz Augusto von Dentz wrote:
> Hi Colin, Tanu,
> 
> On Sun, Nov 17, 2013 at 3:17 PM, Colin Guthrie <gmane at colin.guthr.ie> wrote:
> > 'Twas brillig, and Tanu Kaskinen at 16/11/13 08:51 did gyre and gimble:
> >> On Fri, 2013-11-15 at 09:31 +0100, Colin Guthrie wrote:
> >> I haven't concentrated on the patches enough to even know what
> >> problem you're solving - is it just that the assertion makes you
> >> nervous, or is there some other benefit.
> >
> > I'm not solving any specific problem per-se. I'm just looking at several
> > bugs where incorrect profiles appear to be selected by default on first
> > boot where HDMI is picked over regular analog output (for those alsa
> > cards which share a single card for both HDMI and Analog output rather
> > than having it presented as separate cards) despite HDMI having a lower
> > priority. This lead me to look at this code and got me thinking - this
> > is the only reason for the patch.
> >
> > A further complication to my current bugs is that sometimes Headphone
> > *ports* are picked by default on first boot even when they are
> > unavailable and again are not the highest priority port. It seems like
> > the same problem but in a different, but similar, part of the code. This
> > is why the second set of patches applied the same logical fixes to the
> > Sink/Source code that Luiz added to the Card profiles. I think it makes
> > sense to keep these bits of code approximately in sync regardless of the
> > outcome of this discussion - the same logic should apply.
> 
> I can try and apply the same logic to Sink/Source, it just that
> overall this kind of policy should be in one place or then remove it
> altogether and make sure the list is always ordered by their module so
> the core should just pick the first one, the problem we were trying to
> solve was that there is no hook for priority changes thus they are
> considered static which is probably why we are relying on
> pa_card_set_profile_available +
> PA_CORE_HOOK_CARD_PROFILE_AVAILABLE_CHANGED to indicate the profiles
> changes.
> 
> So perhaps we should came to an agreement where and how we should be
> doing this sort of policy, we could perhaps generalize
> module-bluetooth-policy, or do we want to continue with per technology
> policy?

I don't think the policy in module-bluetooth-policy is useful outside
Bluetooth. module-bluetooth-policy is mainly concerned with the
transport state in its policy, and the profile availability is only used
as a proxy for the transport state. I'd be happy if
module-bluetooth-policy would be changed so that instead of using the
profile states, it would directly track the transport states using the
APIs that pa_bluez_discovery provides. But since using the profile
states as a proxy works fine too, I'm not really asking anyone to do
anything about that.

>From the proposed changes, I think Colin's patches 1 and 3 make sense.
Preferring PA_AVAILABLE_YES over PA_AVAILABLE_UNKNOWN in generic code
isn't a good idea.

-- 
Tanu