USB WEBCAM causes soundcard problems
 

I have a strange soundcard that hardly works under linux, namely Turtle Beach montego. However, it is working with an aureal driver I found and everuthing was fine...
Now for my birthday I got a webcam, the logitech quickcam pro 3000, wich under linux has a seperat standars usb audio microphone, and it causes problems!!! The webcam works fins, and everything works really good if i connect the webcam AFTER the computer starts up, but if i have it connected when i start the computer then problems occur. The soundcard stops to function, and the only mixer I can access is the one for the usb audio microphone! WHY???

Is there a way to fix this?? Will I always haveto disconnect my webcam when starting up? Is there a way to 'hide' the webcam shile starting up, to similate disconnecting it?

Help me, please! It's a really nice webcam, and I'd like to be able to use it without getting anoid everytime I start my computer!

Sounds like a IRQ conflict, both Sound card and camera use same IRQ and since soundcard is initialized first, then webcam after it the webcam screws the sondcard, but if you connect the webcam after it will use another IRQ and leave the poor soundcard alone. You will have to look at /proc/interrupts and figure out which interrupt is used by both devices, then recompile your kernel and add webcam support AS A MODULE and then load it with IRQ= option, and put it to another (free) IRQ.
I realize this is confusing, but it's the only way i can think of right now. But before doing it wait and see if someone has a simpler solution on how to force a device to use a different IRQ.

-NSKL

Hmm...
 

I think the webacam is not the problem, but the SOUND-part (another logical unit). But I am not entirely sure...

It is the audio driver, as I've found out tonight. I've been beating my head against this all night. I could boot up fine, but my sound card would need to be reconfigured each time for it to work. After poking around a bit I noticed with dmesg that an audio driver was being loaded during the USB startups. I remembered the trouble I had when I first installed my quickcam on windows where it's microphone would always take the line-in away from my headset mic. I solved that problem by disabling the cam's mic.

So I did a search on the PWC driver that linux loads for the Logitech and came up with this link which describes how to disable the mic on the cam during bootup. It works for me now, your mileage may vary.

Sorry, I forgot one thing.

At the end of his usbaudiooff script you need to load your soundcard drivers. You can do that with the following lines placed after the line "esac"

/sbin/modprobe cs46xx
RETVAL=$?
if [ "$RETVAL" -eq 0 ]; then
success "Enable PCI Soundcard -"
else
failure "Enable PCI Soundcard -"
fi

I'm loading the cs46xx sound card drivers, yours might be different.

I'm still looking for a more elegant solution to this problem. The audio.o driver that is causing the problem still gets loaded at startup. This script just turns it off and loads the sound card.