[Pkg-alsa-devel] Bug#742412: USB Webcam Grabs ALSA Card Index 0

[Rainer Dorsch]

Hi Elimar,

Am 06.05.2014 00:14, schrieb Elimar Riesebieter:
> * Rainer Dorsch <ml at bokomoko.de> [2014-04-07 22:49 +0200]:
>
>> On Sunday 06 April 2014 22:39:28 Elimar Riesebieter wrote:
>> [...]
>>> Please leave me a note whether you are happy now. So I can close
>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=742412
>> I will look into it next weekend again, and then update the bugreport.
> Any suggestion?
>
> Elimar

I did not find a lot of time to look into this, current status is:

One issue I found in alsa-base is that alsa-base blocks only one device 
which uses snd_usb_audio (and I had plugged two, a webcam and a headset):

rd at blackbox:/etc/modprobe.d$ cat alsa-base.conf | grep snd-usb-audio
# Keep snd-usb-audio from beeing loaded as first soundcard
options snd-usb-audio index=-2
rd at blackbox:/etc/modprobe.d$ cat alsa-base-local.conf | grep snd_usb_audio
#options snd slots=snd_usb_audio,snd_hda_intel
options snd_usb_audio index=-2,-2
rd at blackbox:/etc/modprobe.d$

This made at least the problem go away that the webcam grabs ALSA Card 
Index 0.

See also http://sourceforge.net/p/alsa/mailman/message/32193640/

The suggestion is to change alsa-base.conf to

options snd-usb-audio index=-2,-2,-2,-2,-2,-2,-2,-2

to bloack 8 snd_usb_audio devices instead of one.

I still need to verify if this makes the reported problem go away. I 
need to reinstall and configure pulseaudio for this.

Thanks,
Rainer

-- 
Rainer Dorsch
http://bokomoko.de/