Can't unload snd_uaudio: it hangs in D+ state

Hans Petter Selasky hselasky at
Mon Apr 23 05:55:54 UTC 2012

On Monday 23 April 2012 02:51:48 Yuri wrote:
> I was debugging Logitech C910 webcam.
> 1. 'kldload snd_uaudio' while camera was attached
> 2. ran webcamd, which worked
> 3. stopped webcamd
> 4. 'kldunload snd_uaudio' while the camera is still attached => hanged in
> D+ 5. 'kldstat' also hangs in D+
> I didn't really use usound, just loaded the module.
> What is wrong with snd_uaudio?


If it says in dmesg that an application is using a device, that is a problem 
with the PCM layer, that doesn't support detach of devices if they are in use.


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