Story of a Desktop User

[Kevin Oberman]

On Tue, Nov 19, 2013 at 7:20 PM, Adrian Chadd <adrian at freebsd.org> wrote:

> The newer sound stuff has a whole bunch of interesting interconnects
> internally that let you wire things around between functional blocks,
> inputs and outputs.
>
> I seem to recall that sometimes you have a hardware-only jack that
> does this. Sometimes its a software only thing where the hardware has
> a switch that the software uses to flip the output wiring.
>
> So depending upon the chipset and what it implements, it may be some
> automagic wiring done by the driver that's enumerated at boot time.
> Boot with -v and see if you get this nice verbose output from the
> sound driver explaining how all the connections are wired up.
>
>
>
>
> -adrian
>
>
> On 19 November 2013 06:23, Julian H. Stacey <jhs at berklix.com> wrote:
> > Eitan Adler wrote:
> >> The hardware switches from speakers to headphones automagically when I
> >> plug in headphones.  I like this behavior but it would be great if
> >> there were a sysctl to disable it.
> >
> > If it's a mini jack that may be an artifact of the socket,
> > in which case no software can control it.
> >
> > Cheers,
> > Julian
> > --
> > Julian Stacey, BSD Unix Linux C Sys Eng Consultant, Munich
> http://berklix.com
> >  Interleave replies below like a play script.  Indent old text with "> ".
> >  Send plain text, not quoted-printable, HTML, base64, or
> multipart/alternative.
> >     Extradite NSA spy chief Alexander.
> http://berklix.eu/jhs/blog/2013_10_30
>

On most sound systems using snd_hda you can do this fairly easily, though
figuring out the exact incantations can require a bit of reading and
thought. Details (including sysctls) may be found in snd_hda(4).

-- 
R. Kevin Oberman, Network Engineer
E-mail: rkoberman at gmail.com