[PlanetCCRMA] disabling specific USB audio interface

Hector Centeno hcengar at gmail.com
Wed Feb 20 19:39:00 2008


Hi,

I recently bought a USB keyboard without realizing it had a built-in
audio interface. Alsa loads it (using the snd-usb-audio module) and
actually kind of works (a lot of xruns) but I don't really want to use
it and it messes the sound routing since some apps insist in doing
their output through it (like the "play" command which is used for
tooltip audio preview in Nautilus and the Flash player in Firefox). I
already set it to the highest index and made sure is not selected as
default in the gnome sound preferences (both Sound Preferences and
Audio Configuration) but keeps causing these routing problems. Is
there a way of completely disabling it without blacklisting
snd-usb-audio in /etc/modprobe.conf? I have a M-Audio USB interface
that I would like to be able to plug in and use. (I'm using Fedora 8).

This is how my modprobe.conf is right now:

options snd cards_limit=8
alias snd-card-0 snd-hda-intel
options snd-hda-intel index=0
alias snd-card-1 snd-usb-audio
options snd-usb-audio index=1

and:

$ sudo cat /proc/asound/cards
 0 [Intel          ]: HDA-Intel - HDA Intel
                      HDA Intel at 0xfebf8000 irq 22
 1 [Audio          ]: USB-Audio - USB Audio
                      Elan USB Audio at usb-0000:00:1d.7-2.4, full speed

Thanks,

Hector