[linux-audio-user] Using index=n option to assign Alsa drivers to card 0, card 1

[Joel Roth]

Hi List'ers

I have two sound cards, using the via82xx and ice1712
drivers.

Here is how they come up in the /proc/asound/cards:

0 [DSP24          ]: ICE1712 - Hoontech SoundTrack Audio DSP24
                     Hoontech SoundTrack Audio DSP24 at 0xdc00, irq 11
1 [V8237          ]: VIA8237 - VIA 8237
                     VIA 8237 with VIA1617A at 0xd000, irq 11
[yes, i see the shared interrupt]

And here are the drivers: 

$ cat /proc/asound/modules

0 snd_ice1712
1 snd_via82xx

Now I want to reverse that, and make the assignments fixed.

According to http://alsa.opensrc.org/MultipleCards
a reliable way to do so is to use the index=n option 
when loading the driver. I believe this is normally
done by using modutils to set options in /etc/modules.conf: 

$ grep index /etc/modules.conf

# Prevent abnormal drivers from grabbing index 0
options snd-bt87x index=-2
options snd-atiixp-modem index=-2
options snd-intel8x0m index=-2
options snd-via82xx-modem index=-2
# Set Via card to index 0, ICE1712 to index 1
options snd-via82xx index=0
options snd-ice1712 index=1

This configuration doesn't work as expected, I get the
result above in /proc/asound/cards. Can anyone
suggest something I might be missing? 

Further downstream there are aliases usages like:

snd-card-0 snd-via82xx
snd-slot-0 snd-card-0

I would consider playing with them, except that I don't see
these incantations/conventions defined anywhere in the Alsa
docs or wiki.

This seems like a FAQ; I'll be sure to post any novel solution 
or insight to the wiki.

Regards,

-- 
Joel Roth