Talk:MultipleCards

From the ALSA wiki

Latest revision as of 23:31, 4 December 2010

This page needs a forest fire

A forest fire, if regularly occurring, helps to keep forests healthy and functioning. It's a forced reset when things have grown too messy. This page has gotten to the state where burning it down and starting afresh looks like a good idea. Hackerb9 10:24, 5 December 2010 (EST)

Major rewrite

Ouch, this page need a major rewrite. It has 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.

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

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
}

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

Multiple PCI cards of the same type?

Is it even possible? The current text implies it is, but doesn't say how. Does one use lspci to get the ID? I tried playing around with loading PCI sound modules and specifying the ID and index, with no luck. On the other hand, it may not be worth the time to investigate this. If there's not a well known fix, maybe it's never a real-world problem. Hackerb9 10:27, 5 December 2010 (EST)