[ubuntu-studio-users] USB device order/naming

[Ralf Mardorf]

On Mon, 10 Nov 2014 11:05:21 +0100
Thijs van severen <thijsvanseveren at gmail.com> wrote:
> What is the recommended way to force a USB audio device to always use
> the same name ? (dev1, dev3..)

devX? If it should be hw:X, then you can try this:

[rocketmouse at archlinux ~]$ cat /etc/modprobe.d/alsa-base.conf
# ALSA module ordering
options snd slots=snd_hdspm,snd_ice1712,snd_ice1712

Explanation:

I've got three audio cards, a HDSP and two Envy24 cards, internal
audio is disabled by the BIOS settings.

The HDSP always becomes hw:0, the Envy24 cards always will become hw:1
and hw:2. Even if I unload the snd_hdspm and/or snd_ice1712 modules,
hw:0 to hw:2 are always reserved, any first audio USB device I plug in
will become hw:3.

IOW, if you add all sound devices drivers of others than USB audio
devices to cat /etc/modprobe.d/alsa-base.conf, one USB device always
will become the same hw:X, after the reserved hws. If you're using more
than one USB devices, it could be an issue. Perhaps it could be solved
by an udev rule.

You also could add snd_usb_audio at the first position, so if you're
using just one USB audio device, it always will become hw:0.

JFTR the index method is obsolet, use the above mentioned slot method
instead.

Hth,
Ralf