[alsa-devel] explicit commandline control of speakers vs headphone output
eric_holstege at yahoo.com
Fri Aug 27 21:49:41 CEST 2010
Thanks for the info. (FYI, I have a Windtop 2200 All-in-one touchscreen,
on which I'm building an appliance with, among other things, VOIP phone
and answering machine capability). I want the user to be able to "put
the call on speaker" even if the mic/headphone handset is plugged in.
Can amixer override this automuting. Is it that the driver just sets the
speakers to mute *at the time* the headphone is plugged in, or does it
force them mute *so long as* the headphone is plugged in?
Or, regarding the pin_configs possibility, I guess I somehow edit
(or maybe user_pin_configs?). Could one point me to documentation on
what the bits mean? Mine are:
David Henningsson wrote:
> 2010-08-27 20:46, Eric Holstege skrev:
>> Thanks, Clemens;
>> How were you able to determine that from the "amixer scontents" output.
>> Although I can't disable *automatic* speaker mute on headphone
>> insertion, can I explicitly unmute them again (e.g. with amixer sset or
>> If not....
>> "cat /proc/asound/card*/codec*" says it is the Realtek ALC888.
>> Does this mean I have to somehow patch the kernel sound module file
>> to fix this somehow?
> So in the long run, I think it would be better to leave all auto-muting
> to userspace. Then stuff like pulseaudio could to advanced decision of
> how to handle input events. But that's the long way.
> There are certainly ways to disable auto-muting for Realtek ALC888, look
> along the lines of "speaker_automute" and "unsol_event". It is also
> possible that you could tweak your user_pin_config to trick your HP out
> into a Line Out. That way it won't automute, and you don't have to
> recompile your kernel.
> As a side note: The VIA HDA driver, I believe, have an option for
> turning automute off. But it also sets "mute" on a misnamed control at
> the same time, tricking PA into believing that you want to mute all
> output. So PA is "helpful" and mutes everything else as well. :-/
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