2.6.39.2: alsa question: usb sound/card shows up as mixer1/audio1?

2.6.39.2: alsa question: usb sound/card shows up as mixer1/audio1?

[Justin Piszcz]

Hi,

Is this a simple udev issue or something else?
I bought two of these but they are actually different devices, on one host 
it works ok, on the other, I get this:

p34:~# dmesg|grep -i audio
[   15.499078] usb 2-2.4: Product: C-Media USB Audio Device
[   15.500235] input: C-Media USB Audio Device    as 
/devices/pci0000:00/0000:00:1d.7/usb2/2-2/2-2.4/2-2.4:1.3/input/input5
[   15.500416] generic-usb 0003:0D8C:0008.0003: input,hidraw2: USB HID 
v1.00 Device [C-Media USB Audio Device   ] on usb-0000:00:1d.7-2.4/input3
[   15.534185] usbcore: registered new interface driver snd-usb-audio
p34:~# ls /dev/mixer*
/dev/mixer1
p34:~# ls /dev/audio*
/dev/audio1
p34:~#

$ cat /proc/asound/cards
  1 [Device         ]: USB-Audio - C-Media USB Audio Device
                       C-Media USB Audio Device at usb-0000:00:1d.7-2.4, 
full speed

On the working host:
$ cat /proc/asound/cards
  0 [Device         ]: USB-Audio - USB PnP Sound Device
                       C-Media Electronics Inc. USB PnP Sound Device at 
usb-0000:00:1d.7-2.4, full spe

--

$ aumix

aumix:  error opening mixer: No such file or directory

--

Any clue why one is mapped to [1] and the other [0], where the one that is 
[0] works properly and the [1] does not?

Justin.

Re: 2.6.39.2: alsa question: usb sound/card shows up as mixer1/audio1?

[Clemens Ladisch]

Justin Piszcz wrote:
> I bought two of these but they are actually different devices, on one host 
> it works ok, on the other, I get this:
> ...
> $ cat /proc/asound/cards
>   1 [Device         ]: USB-Audio - C-Media USB Audio Device
>                        C-Media USB Audio Device at usb-0000:00:1d.7-2.4, full speed
> 
> On the working host:
> $ cat /proc/asound/cards
>   0 [Device         ]: USB-Audio - USB PnP Sound Device
>                        C-Media Electronics Inc. USB PnP Sound Device at usb-0000:00:1d.7-2.4, full spe
> 
> Any clue why one is mapped to [1] and the other [0], where the one that is
> [0] works properly and the [1] does not?

Some distributions configure USB devices to not load at index 0 to
prevent conflicts with the primary PCI sound card.  Have a look into
/etc/modprobe.d/.


Regards,
Clemens

Re: 2.6.39.2: alsa question: usb sound/card shows up as mixer1/audio1?

[Justin Piszcz]

On Fri, 22 Jul 2011, Clemens Ladisch wrote:

> Justin Piszcz wrote:
> > I bought two of these but they are actually different devices, on one host 
> > it works ok, on the other, I get this:
> > ...
> > $ cat /proc/asound/cards
> >   1 [Device         ]: USB-Audio - C-Media USB Audio Device
> >                        C-Media USB Audio Device at usb-0000:00:1d.7-2.4, full speed
> > 
> > On the working host:
> > $ cat /proc/asound/cards
> >   0 [Device         ]: USB-Audio - USB PnP Sound Device
> >                        C-Media Electronics Inc. USB PnP Sound Device at usb-0000:00:1d.7-2.4, full spe
> > 
> > Any clue why one is mapped to [1] and the other [0], where the one that is
> > [0] works properly and the [1] does not?
> 
> Some distributions configure USB devices to not load at index 0 to
> prevent conflicts with the primary PCI sound card.  Have a look into
> /etc/modprobe.d/.
> 
> 
> Regards,
> Clemens
>

Hi,

That was it, thanks.

Justin.