Arch Linux

Padfoot

Member

Registered: 2010-09-03

Posts: 381

[SOLVED] ALSA Default card issue

Hi,

A sound issue has today creeped onto my system, and I am interested if anyone can explain why this is happening.

My sound has always worked perfectly OOTB, but today, suddenly I have no sound (not pulseaudio - I don't have any of that on my system).
After a little playing around - along with some guess work, I discovered that for some reason, upon boot, alsa now sets a USB webcam microphone as the default (card 0) and the onboard sound as card 1.

So I have solved my issue by creating ~/.asoundrc which switches the devices. Now upon logging into my session, sound is working again.

My question is, why. Why is alsa suddenly deciding to default to a USB microphone instead on the onboard sound card (onboad intel)??

It does not make sense to me that a USB sound device would be picked over onboard sound at anytime. To me, that appears to be something that should be "hardcoded" - default to onboard sound ALWAYS unless it is not present, then all other devices are secondary.

Anyway, hopefully someone is able to answer this, and possibly provide a solution. In my mind, having to set ~/.asoundrc should not have to be done as this will need to be created for every user on the system, and maintained should anything change again.

Just a thought, could it possibly have something to do with kernel sound module loading order?

Cheers.

Last edited by Padfoot (2011-10-01 00:15:36)

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: [SOLVED] ALSA Default card issue

Indeed it has to do with kernel module loading order. The usual solution is using module parameters. So create /etc/modprobe.d/alsa.conf:

options snd_hda_intel index=0

If that's not enough, also add

options snd_usb_audio index=1

Last edited by Gusar (2011-10-01 00:01:50)

Padfoot

Member

Registered: 2010-09-03

Posts: 381

Re: [SOLVED] ALSA Default card issue

@Gusar

Thank you, that has certainly got my sound working globally again.

But that now raises the question, why has the module loading order changed to create this issue in the first place?

Cheers.

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: [SOLVED] ALSA Default card issue

But that now raises the question, why has the module loading order changed to create this issue in the first place?

Modules load in parallel. Which modules will finish loading before or after any other module on a particular boot is up to many factors, possibly including the phase of the moon

Padfoot

Member

Registered: 2010-09-03

Posts: 381

Re: [SOLVED] ALSA Default card issue

LOL......HOWLLLLLLLLLLL (is it a full moon?)

Just seems so odd that in all my time running Arch, this has never been a problem and now, every boot...well you know the rest.

Anyway, looks like I'll just have to keep a copy of /etc/modprobe.d/asla.conf in my backup config directory (I have a backup config directory on a separate device that holds copies of every system config file I have changed for my system - handy in the case of a re-install as I know exactly what setup needs to be done).

Cheers.