[Alsa-user] Alsaconf es18xx Mystery

[Dave W. <jd...@ex...>]

Hello Alsa Users -

I've discovered a strange situation on a machine I own.  It's an old
Compaq Presario 4505 that I received as a gift back in 98.  It was
running Win95 for a long time, but I finally decided to liberate it with
Slackware 9.1

The machine was built with the ES1887 Plug and Play Audiodrive, an old
ISAPnP legacy card that Alsa can operate via the snd-es18xx driver.  The
resources for the device are actually set in the BIOS, because as some
of you may remember Microsoft wasn't able to completely force
plug-and-play BIOS specifications on manufacturers where soundcards were
concerned.

I know some people will wonder why I'm bothering to work with this
machine, but I like it and enjoy the challenge.

The problem is this: The kernel (Slackware's standard 2.4.22) doesn't
recognize the card when it boots.  The command "insmod" fails.  And
"modprobe" says there's no such device.  This happens no matter how
carefully I specify the card options and parameters (which are in the
BIOS, remember, and there are no resource conflicts).

Now here's the mystery: I run alsaconf and tell it to probe for legacy
ISAPnP cards (specifically the es18xx) using any available DMAs and IRQs
and it fails.  BUT when I check with lsmod the module is installed and
it works correctly!  All the dependencies are available except for the
oss compatibility stuff, which I can install from there.

My question is: What is alsaconf doing that makes it successful in spite
of itself?  And how can I reproduce it?

I've been going over the alsaconf script and I just can't see the
secret.  Then again, I'm not especially good at reading shell scripts. 
I've searched Google and the archives and found occasional references to
similar problems with the module, but no explicit solutions.  Someone
mentioned recompiling the libraries in one thread, but shouldn't a
default kernel with a default alsa install be appropriately matched up? 
And after all, the card does end up working!

This is the last little hassle remaining before this machine is 100%, so
if anyone can figure out how alsaconf is installing my soundcard I will
be eternally grateful.

- Dave