Cmedia USB audio

sdfi · 10-17-2011, 04:25 PM

OS: voyage linux (minimal, based on debian 6). Trying to get my usb 'audio card' to work.

lsusb -v lists it as;

Code:

C-Media Electronics, Inc. Audio Adapter (Planet UP-100, Genius G-Talk)

Although it is one of these not a usb headset like the 'Planet UP-100' seem to be. But there doesn't seem to be a specific chip name??

There is a guide i believe for this thing at http://www.fuschlberger.net/cds/usb-audio/ But this guide is from 2005 so i'm not sure if it is still relevant??

It mentions snd_usb_audio is required, how do i check to see if i have this??

EDIT: aplay -l outputs

Code:

no soundcards found...

EDIT 2: modprobe snd-usb-audio

Code:

snd_usb_audio not found.

How do i add this? does it have to be added in the kernel?? (if so, under what section is it?)

EDIT 3: ID is 0x0d8c 0x000e

business_kid · 10-18-2011, 02:06 AM

sind snd-usb-audio by doing a find in ;/lib/modules (fine -name snd_usb_audio.ko') or use locate or slocate if they're there.

You may need to add a device node to udev if the system doesn't have it. Have a look in the kernel ~Documentation/sound directory for helpful stuff.

sdfi · 10-18-2011, 08:11 AM

the find returned nothing.

sdfi · 10-18-2011, 05:36 PM

Any ideas? I couldn't find much about installing snd-usb-audio, or find anything about it in the kernel builder, and there was nothing about installing it in the docs that i found. ???

business_kid · 10-19-2011, 01:55 AM

No usb card here, but a bit of stuff on the disk. I ran 'locate snd-usb-audio'

It lives in ~kernel/sound/usb/snd-usb-audio.ko in the module tree
In the 2.6 kernel it's in ~sound/usb/

In the kernel .config, It's in the very end of the sound menu after all the cards. It exists.

sdfi · 10-19-2011, 07:19 AM

I couldn't locate it via 'make menuconfig', but in the .config file (which I assume menuconfig is just a frontend for?) CONFIG_SND_USB_AUDIO=m ..which means it should be there, right??

edit: it is under the 'console display driver support' section (of .config), wtf?"

edit 2: when plugging in the device ;

Code:

USB 4-1: new full speed USB device using uhci_hcd and address 2
usbcore: registered new interface driver usbhid
usbhid: USB hid core driver

business_kid · 10-20-2011, 02:21 AM

Quote:

Originally Posted by sdfi

I couldn't locate it via 'make menuconfig', but in the .config file (which I assume menuconfig is just a frontend for?) CONFIG_SND_USB_AUDIO=m ..which means it should be there, right??

No, that's not where I found it. It's in drivers --> sound -->Alsa -->USB sound devices as "USB audio/MIDI driver".

It depend on SOUND[=y] && !M68K && SND[=y] && USB[=y] This means if you haven't got those you mightn't see it!

Quote:

Originally Posted by sdfi

edit: it is under the 'console display driver support' section (of .config), wtf?"
edit 2: when plugging in the device ;

Code:

USB 4-1: new full speed USB device using uhci_hcd and address 2
usbcore: registered new interface driver usbhid
usbhid: USB hid core driver

No, I'm not impressed with your sound card being grabbed by the HID driver. . . I'm afraid something is not perfect yet. They have acknowledged it's existence, which at least means it's connected. uhci_hcd is the usb-1.0 driver. I'd like to see it being grabbed by ehci_hcd which is usb-2.0.

Maybe ehci couldn't figure it, and dropped out throwing it at the usb-1.0 driver? That then woke up and said "Oh good, something for me to play with."

sdfi · 10-22-2011, 10:57 AM

I couldn't find any reference to M68K, but i set as you suggested to y and rebuilt, and it work now

[aside: what is the different between m and y?... AFAICT y is in the core kernel and m is a module?? what is the practical result of this?]

Now, the only issue here remaining is that i cannot set the volume level now with mpc /mpd, despite the fact that it is possible to set it with 'alsamixer -c 0' Any ideas how do deal with this??

[aside 2: setting the volume to -0.1 db with alsamixer shouldn't introduce distorition should it??.. i only ask as the volume is shown in green/white/red as you increase the volume].

business_kid · 10-23-2011, 03:54 AM

/exposes himself as a mine of useless knowledge:-P.

m68k is the old cpu type used in Apple Macs before they went to the ppc, and then intel. It is/was Motorola's 58000 series - good for the '70s and '80s but not a great idea thereafter. You haven't got it.
Yes, 'm' is module and 'y' is compiled in. Long debate about which is better. If it starts on this thread I will unsubscribe from it :-).

Quote:

Now, the only issue here remaining is that i cannot set the volume level now with mpc /mpd, despite the fact that it is possible to set it with 'alsamixer -c 0' Any ideas how do deal with this??

Nope.

Quote:

[aside 2: setting the volume to -0.1 db with alsamixer shouldn't introduce distorition should it??.. i only ask as the volume is shown in green/white/red as you increase the volume].

I wouldn't think so. There are internal volume levels of a sort (The signal on this pin is 50mV pk-pk or 200mv pk-pk sort of thing) which are really in gobbledygook in alsa.conf AFAIK.

Now that you have your sound drivers, if you're having distortion, best to delete the soundcard and reinstall it to clear the config, in case you have some default settings.