[alsa-devel] Signaling user-space through kcontrol

Vinod Koul vinod.koul at linux.intel.com
Wed Sep 28 09:03:32 CEST 2011

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


More information about the Alsa-devel mailing list