Re: [linux-audio-user] Alsa sound card order.

On Tue, 2007-01-02 at 21:24 -0800, St wrote:
> So, after rebooting many times, and answering the nvidia
> driver questions as many times, I still wonder about the
> issue of card order. Right now all is ok, but I've heard
> many reports of card order swapping from boot to boot. Not
> so hot.

You can give every device their own card slot, regardless of the order
they are discovered in. This is an excerpt from my /etc/modprobe.conf:

alias sound-slot-0 snd-emu10k1
alias sound-slot-1 snd-cmipci
alias sound-slot-2 snd-usb-audio
alias sound-slot-3 snd-usb-audio
alias sound-slot-4 snd-usb-audio

options snd-emu10k1 index=0
options snd-cmipci index=1
options snd-usb-audio index=2,3,4 vid=0x0A4D,0x17A0,0x0c45
  pid=0x0090,0x0001,0x60AF

(that's not supposed to be a line break before "pid")

The "index" options tells the driver modules which sound card slot the
devices using that driver should be loaded into, and the vid and pid
options for the USB module specify which particular USB devices
(specified by their vendor and product IDs) should be loaded into slots
2, 3, and 4 (in this case a MIDI keyboard, a microphone and a webcam).

If the keyboard is discovered first it will still get loaded into slot
2, if the emu10k1 is loaded second it will still get loaded into slot 0,
etc. Provided, of course, that no other device has already been loaded
into slots 2 or 0 - so in order for this to work you have to specify
indices for all devices you may connect. It would be better if there was
some sort of central 'device -> slot number' mapping so that modules for
new devices automatically knew that they should avoid indices 0 to 4,
but I don't think there is.

-- 
Lars Luthman - please encrypt any email sent to me if possible
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