[pulseaudio-discuss] [PATCH] alsa-mixer: Don't let "Mic Jack Mode" alone create a "Line In" path

[David Henningsson]

On 10/17/2012 03:21 PM, Tanu Kaskinen wrote:
> On Wed, 2012-10-17 at 14:55 +0200, David Henningsson wrote:
>> Yes, setting "Mic Jack Mode" to "Line" would turn of the VREF pin of the
>> codec, i e, the phantom power to the microphone. In "Mic" mode there's
>> usually a phantom power of 80% of Vdd. (I have never actually measured
>> this - I'm just looking at the HDA spec.)
>>
>> So my argument is more about confusion ("Hey, PulseAudio says I've got a
>> line in port, but I don't have one, let's file a bug!").
>
> Which scenario do you mean:
>
> 1) The user complains, because he sees a line-in port even though
> nothing is plugged in

That's the current situation.

> or
>
> 2) The user complains, because he sees a line-in port even though the
> the connector has only a mic symbol, and not a combined mic & line-in
> symbol?

The user complains because he sees *both* a line-in port and a mic port, 
even though he only has one port (with a mic symbol on it).

> If you mean scenario 1, do you agree that having two ports would be
> better, if both get marked unavailable when nothing is plugged in? (It's
> probably not so easy to write the code to implement that, and if I had
> to choose between the one-port solution and no solution at all, I'd
> choose the one-port solution.)

I'm a bit hesitant myself about which one is better; have two ports 
showing up at plug in, or just the mic one.

Also, it is not very difficult to write a new path or two to cover this 
specific scenario, but I'm also starting to feel that the model for 
paths is starting to get difficulties to scale.


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic