On 08/21/2012 02:05 PM, Mark Brown wrote:
On Tue, Aug 21, 2012 at 07:28:34AM +0200, Takashi Iwai wrote:
Ricardo Neri wrote:
I was wondering about how much sense does it make to you guys use a
snd_soc_jack in this case?
HD-audio already uses the generic jack event for the HDMI/DP
connection change notification as well, so I think it would make sense
in general.
The whole problem here is that we don't *have* a generic jack interface.
We've got:
- sound/core/jack.c which was written to be a generic API and is used
by everything that does jack support currently.
- sound/core/ctljack.c which was added later and provides separate
in-kernel and userspace APIs and is currently only used by HDA.
This is wrong. PulseAudio uses the new ctljack API. I started out with
an implementation which used the input device API (sound/core/jack.c),
but since some people did not like this API, the ctljack API was
designed and implemented for PA to use, which it does (since PulseAudio
2.0 - the input device API implementation in PulseAudio was never merged
upstream).
- extcon which does have a good reason to be a separate API since that
it's not audio specific (and is likely to be picked up by Android as
the code was originally taken from there); it's currently not
supported by the frameworks in ALSA. I'd suggest Pulse should be using
it too.
This is a complete shambles for both driver authors and userspace, the
ABI varies randomly with drivers and in theory driver authors have to
implement everything three times which is just nuts.
What I'd like to see happening is that we merge ctljack into jack (since
only HDA is going to be affected by that change it seems like the right
direction to make the merge) and also add extcon support, I have looked
at the extcon support.
I don't know either why we have two different interfaces for jack
detection (not counting extcon) for driver writers. I think we should
merge jack and ctljack, as long as that does not mean you break anything
I'm relying on in ctljack.
Maybe something for discussion at Plumbers?
Short term for drivers used on embedded systems I'd have to recommend
extcon rather than anything ALSA-specific.
I thought that when Takashi did the new ctljack interface, that would
effectively deprecate the old input device interface, and that ctljack
was the new recommendation.
--
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic
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