Re: [alsa-devel] [PATCH v4 0/5] ALSA: jack: Refactoring for jack kctls

-----Original Message----- From: David Henningsson [mailto:david.henningsson@canonical.com] Sent: Wednesday, April 08, 2015 3:21 PM To: Takashi Iwai; Jie, Yang Cc: alsa-devel@alsa-project.org; broonie@kernel.org; Girdwood, Liam R Subject: Re: [alsa-devel] [PATCH v4 0/5] ALSA: jack: Refactoring for jack kctls

On 2015-04-07 18:06, Takashi Iwai wrote:

...

This would work, yes. But, I have some uneasy feeling, something not well digested...

Ideally, we want a single API for representing both input and kctl jacks.

Maybe this is somewhat my fault for steering Yang in that direction. But the requirements are somewhat different.

HDA has the phantom jacks, and the exact naming for each kctl requirements. ASoC has the combination/button requirements, i e one jack can represent more than one kctl.

The phantom jack requirement means that the snd_kctl_jack_new API cannot be removed straight away; we could move it to be internal to HDA (it's not much code anyway), but I don't see a need for that.

But the HDA code can be moved around to look like this:

if (phantom_jack) {
   snd_kctl_jack_new();

Let me add line here to clarify: + snd_hda_ctl_add();

}
else {
   snd_jack_new();
   snd_jack_add_new_kctls();

I thought of this at the beginning, as you talk below, it looks more like what we did for ASoC case.

What I concern here is that it may make input jack kctl looks like a little different with before(I am not sure, maybe you guys are more clearly about what will occurs without calling snd_ctl_add()-->snd_array_new()...)?

}

Now the HDA looks more like the ASoC variant. Yang, what do you think about that? That would make the API simpler, wouldn't it?

Here repeat what I stated in another reply:

For jack creating, we use the same API -- snd_jack_new();

For kctl creating, yes, we use different APIs: snd_jack_kctl_new() for input jacks(HDA), snd_jack_add_kctls() for kctl jacks(ASoC).

There are 2 reasons that I made them different: 1. a. for HDA phantom jack, in the old/exist logic, __snd_hda_jack_add_kctl() will also call snd_kctl_jack_new() and snd_hda_ctl_add(), it will create kctls and add them to card(also assigning some arrays, they are different with calling snd_ctl_add() only, which is what we will do for ASoC kctl adding); b. for HDA input/phantom jack, all of those occurs before calling snd_jack_new().

So, we have to split jack new and kctl new functions here, because for HDA phantom/input jack and ASoC kctl jack, they are quite different here.

2. we may need generate kctl name for ASoC kctls(snd_jack_kctl_name_gen(), removing suffix " Jack" as you proposed before, or everything needed after); but for HDA input jack kctls, the naming has been finished before calling __snd_hda_jack_add_kctl(), we should not change them anymore.

Thanks, ~Keyon

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