Re: Question, regarding sound initialization with SB16 cards...

Hannu Savolainen (
Fri, 9 May 1997 09:23:24 +0300 (EET DST)

On Fri, 9 May 1997, The Deviant wrote:

> How would I go about changing the default (bootup) mixer settings on an
> SB16, in kernelspace?
> I'm fairly new to working in kernelspace, but I was thinking it would
> probably be a good idea to have the initialization functions set all the
> mixer values to zero, so that if you have multiple output sources, you
> don't need to worry about what plugged in at bootup...
> Case in point, one of my inputs is usually plugged into a radio, and my
> output is often an amplified speaker set, but just as often earphones
> If the speakers are plugged in at bootup, it blairs the radio very very
> loudly for a minute or so until it gets to my rc files (yes, its a slow
> machine)
> Any ideas on how to change this in kernel?
Just change the default volumes given in sb_mixer.h in case you are
looking for a simple solution which works on your computer.

A more general solution is possible when using the driver as a loadable
module with kerneld. There is an almost ready interface for this if
somebody is willing to implement support for this. Just look at how
sound_switch.c. SOUND_MIXER_GETLEVELS call can be used to implement a user
space program that dumps the currently active settings to a disk file.
These settings can then be loaded using kerneld but this needs to be done
before soundcard_init() gets called from soundcard.c.

Best regards,

Hannu Savolainen (, (Open Sound System (OSS)) (OSS Free/TASD/VoxWare)