Memory leak / Kernel Panic using snd_uaudio (USB Sound Card)

Hans Petter Selasky hselasky at
Sat Mar 31 12:44:34 UTC 2007

On Saturday 31 March 2007 14:30, Hofmann, Laurent wrote:
> -----Message d'origine-----
> De : owner-freebsd-usb at [mailto:owner-freebsd-usb at]
> De la part de Hans Petter Selasky
> Envoyé : samedi 31 mars 2007 13:16
> À : freebsd-usb at
> Objet : Re: Memory leak / Kernel Panic using snd_uaudio (USB Sound Card)
> Just do a SVN update and try again. By a mistake I removed a patch for
> FreeBSD
> 6.2.
> --HPS
> Thank you very much. It compiled like a charm. I also included the driver
> in the kernel instead of using it as a module.
> I'm now playing some music, I will tell you if the kernel panic still
> occur...


> Just one more remark :
> The driver is not detected as before :
> uaudio0: <Guillemot USB Audio, class 0/0, rev 1.10/1.00, addr 126>
> uaudio0: Play: 48000 Hz, 2 ch, 16-bit S-LE PCM format
> uaudio0: Record: 48000 Hz, 2 ch, 16-bit S-LE PCM format
> uaudio0: No midi sequencer
> uaudio0: WARNING: Unplugging the device while it is in use will cause a
> panic!
> pcm0: <USB audio> on uaudio0
> dolphin# cat /dev/sndstat
> FreeBSD Audio Driver (newpcm)
> Installed devices:
> pcm0: <USB audio> at ?  (1p/1r/0v channels duplex default)
> Before I had more lines, one of these lines was indicating a 6 channel
> device. Now I have the feeling that only the front channels are available ?

I don't know if the current audio system supports more than 2 channels.

There is a knob in uaudio.c that you can tune:

static u_int8_t  uaudio_default_channels = 2;

But you probably have to add some code to tell the upper sound layers that 
there is more than 2 channels!

> PS : Do you know when these drivers will be included in Freebsd ?

I hoped before 7.0 was out, but it might be later. I am not the one deciding 
that. But if many people like you turn up and tell the list how much faster 
and how much more solid the new USB stack is, then it might happen faster ;-)


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