[alsa-devel] Signaling user-space through kcontrol

[Vinod Koul]

On Tue, 2011-09-27 at 23:47 -0700, Patrick Lai wrote:
> On 9/27/2011 11:15 PM, Vinod Koul wrote:
> > On Tue, 2011-09-27 at 23:14 -0700, Patrick Lai wrote:
> >> Hi Mark,
> >>
> >> The codec I am working on, beside headset detection, also have other
> >> type of events to be propagated to user space. Per our discussion at
> >> IPC, there is way to signal user-space through kcontrol. Is it through
> >> calling snd_ctl_notify()? What is the ALSA library API to intercept the
> >> event? Is there an sample user-space code which gets kcontrol event?
> >>
> > What events do you have in mind?
> >
> Main one is detection of short circuiting headphone For this case,
> there is no need for extra payload. In case of there is need to pass
> back some payload, I presume user-space application can simply call the
> get function upon receiving notification.
And what would userspace do with that information? Apart from logging
this, is there anything useful we can do with such info

-- 
~Vinod