[Glastonbury] ALSA issues

[tim hall]

Last Monday 06 September 2004 23:11, nick irwin was like:
> On Monday 06 Sep 2004 20:12, Andrew M.A. Cater wrote:
> > On Mon, Sep 06, 2004 at 03:00:39PM +0100, tim hall wrote:
> > > Last Sunday 05 September 2004 02:05, nick irwin was like:
> > > >  Turns out you can't start ALSA from rc-update. Nor can you load any
> > > > sound modules until the init phase is complete. Loading any modules
> > > > causes ALSA to think its already been started, when it hasn't. So it
> > > > says, "Sorry, I'm already running" and quits"
> >
> > I've seen this somewhere else. Make sure that you are are _only_ loading
> > alsa modules and not the older oss ones: this may help.
>
> I looked at lsmod's output and I think you may well be right, I certainly
> saw the letters oss a number of times, so now I just have to try and get
> rid of em. Thanks this could certainly help.

ALSA modules all have the prefix snd-
snd-pcm-oss, snd-mixer-oss and similar are OSS compatibility modules for ALSA.
You can do without them and they have been known to cause minor problems, but 
it shouldn't cause problems if you leave them in.
OSS modules on the other hand (i.e. without the snd- prefix) conflict with 
ALSA badly.

Check that the modules aren't being loaded from somewhere like /etc/modules 
(or whatever mdk ==).

> > [For the logic impaired - I and several others thought that sound had
> > vanished on our Debian systems. It turns out that alsa is being
> > correctly configured but that the mixer is turned right down to zero as
> > a default setting.  A bit of aumix / gamix and it all works fine again :)
> > Took a long time and a bit of googling to work that one out :) ]
>
> Yeah I came across that little gem quite a while ago, whoever thought of
> those defaults needs a good lesson in practicality. But no in this instance
> it isn't the sound levels.

It's to prevent accidentally blowing people's speakers up.

Try Austin Acton's Mandrake Digital Audio Workstation HowTo:
http://groundstate.ca/mdkaw
I've not read it, but it hopefully should provide some leads.

Also:
http://alsa.opensrc.org/
is a mine of useful information, the http://alsa.opensrc.org/?aadebug script 
is a useful diagnostic tool, which will usually point up errors that you 
might otherwise have overlooked.

HTH ;-)

tim hall