Hi,

How can I set up Linux on my notebook to recognize when I plug in my USB sound card, switch to it as the default, and then switch back to the on-board sound card once the USB card is unplugged?

I have a notebook with a built-in PCI sound card (snd_hda_intel) and an external USB 5.1 sound card (snd_usb_audio). So far I have been successful in setting up both cards with ALSA and I can play sounds through both of them. However, that is done by having both cards loaded at boot time, which requires the USB card to be connected and set as the default in /etc/asound.conf.

Is there a way to have the system react to the external sound card being plugged in / unplugged? The ALSA Wiki has a HowTo with hotplug, but I am using udev, which is supposed to replace hotplug ...

Thanks,

Marek

udev compliments hotplug.

udev is the way to go.

See: http://www.reactivated.net/writing_udev_rules.html

I had some Bose USB speakers I was going to do this with, but I got too busy with other projects. I just left them plugged in all the time.

You might find some useful information if you search LQ for posts by me containing the text Bose and/or speakers

Please let us know how you get on. If you get stuck, repost here and I'll look through some old files ( if I can find them )

Thank you very much for the links. What I needed to do was create a local udev rule, reacting to audio1 in the sound subsystem that would call my script, which only needed to link /etc/asound.conf to one of the two different configs (internal audio vs. usb audio). More info can be found in my LinuxWiki.

P.S.: I also tried removing and modprobing the kernel modules on plug/unplug and realized that stopping or starting a service also calls udev rules, which then resulted in a nice endless loop (stop service -> udev rule triggered -> started service -> udev triggered -> stop service -> ...).

Thanks for the follow-up post.

Can I take this post to mean that you got it working, eventually ?