Talk:MultipleCards

From the ALSA wiki

[edit] Major rewrite

Ouch, this page need a major rewrite. It is so many approximations in it. I will try to make some corrections.

For any ALSA configuration (I assume ALSA is built as modules), the reference is [file:///usr/src/linux/Documentation/sound/alsa/ALSA-Configuration.txt /usr/src/linux/Documentation/sound/alsa/ALSA-Configuration.txt] from the kernel documentation. If you don't have the kernel sources, this file is with the documentation of the alsa-driver package.

First, somme comments on this page. I will begin them with #

Well, I edited the article. It is mostly done, but I didn't get the time to review the examples section.

[edit] Multiple soundcards in Gentoo

In this setup the cards get a specific order nothing more, the first one (audigy) is the default card which amarok, mplayer,... will use
You could of course also compile the kernel without the second driver.

sample /etc/modules.d/alsa file for multiple soundcards
1. snd-ca0106 (creative audigy ls)
2. snd-intel8x0 (onboard)

options snd-ca0106 index=0
options snd-intel8x0 index=1
#
alias snd-card-0 snd-ca0106
alias snd-slot-0 snd-card-0
alias sound-slot-0 snd-slot-0
#
alias snd-card-1 snd-intel8x0
alias snd-slot-1 snd-card-1
alias sound-slot-1 snd-slot-1

# You did forget 
options snd cards_limit=2

after that you need to run:

modules-update && /etc/init.d/alsasound restart

Howto get the needed information:

(current sound card order can change because udev loads the modules in random order. dont know about drivers compiled in the kernel)

cat /proc/asound/cards

0 [CA0106         ]: CA0106 - CA0106
                     Audigy SE [SB0570] at 0xdf00 irq 19
1 [CK804          ]: NFORCE - NVidia CK804
                     NVidia CK804 with ALC655 at 0xfebfd000, irq 22

(used modules)
cat /proc/asound/modules

0 snd_ca0106
1 snd_intel8x0

[edit] Multiple Sound Cards on Debian, different approach

I did not manage to get the modules config version to solve the problem working, so I took a different approach. I created an init script to determine the desired primary device and change the alsa config accordingly. It tries to find the device from the information available through /proc/asound/modules and creates the /etc/asound.conf.

The latest version of the skript is available here Github Repository - set_alsa_card.sh (just grab the raw version of set_alsa_card.sh)

You just have to ajust the variables according to your needs and place the script in your bootup process. I placed the file to /etc/init.d/set_alsa_card.sh and linked it into /etc/rc2.d/S20_set_alsa_card. After that it creates the config file during each boot. Make sure you don't have a ~/.asoundrc that is interfering with the global config and be aware that the specified config file will be ovewritten.

The following config is created for example:

/etc/asound.conf
# Warning, this file is created by script - do not modify
# or deal with lost changes.
#
# This config makes 'emu10k1' the first card.
#
# Updated: Wed Feb  4 22:36:16 CET 2009

pcm.!default {
  type hw
  card 0
}

ctl.!default {
  type hw
  card 0
}

[edit] USB webcam kills sound card on Debian Lenny box

I found when plugging a Logitech pro 9000 webcam into my debian lenny box that the sound card on the motherboard would randomly be disabled.

If the soundcard was disabled during boot I found this in dmesg

[   10.698812] cannot find the slot for index 0 (range 0-0), error: -16
[   10.698812] Intel ICH: probe of 0000:00:1e.2 failed with error -12

and this if I looked for working soundcards

debdesk:~# cat /proc/asound/cards
0 [U0x46d0x990    ]: USB-Audio - USB Device 0x46d:0x990
                     USB Device 0x46d:0x990 at usb-0000:00:1d.7-2, high speed

My solution was to edit the /etc/modprobe.d/alsa-base file and add this to the bottom

# Keep webcam from being loaded first
options snd_usb_audio index=-2

# good. In some cases (when your solution alone fail), 
it can even be needed to blacklist snd_usb_audio in
/etc/modprobe.d/blacklist.conf, in order to prevent
udev from loading this module before alsasound.

no problems since