SND_UAUDIO(4)						   BSD Kernel Interfaces Manual 					     SND_UAUDIO(4)

NAME

     snd_uaudio -- USB audio device driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel configuration file:

	   device sound
	   device usb
	   device snd_uaudio

     Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

	   snd_uaudio_load="YES"

DESCRIPTION

     The snd_uaudio driver provides support for USB audio class devices.

     A USB audio device consists of a number of components: input terminals (e.g. USB digital input), output terminals (e.g. speakers), and a num-
     ber of units in between (e.g. volume control).

     Refer to the 'USB Audio Class Specification' for more information.

SEE ALSO

     sound(4), usb(4)

     USB Audio Class Specifications, http://www.usb.org/developers/devclass_docs/.

HISTORY

     The snd_uaudio driver first appeared in FreeBSD 4.7.

AUTHORS

     This manual page was adopted from NetBSD 1.6 and modified for FreeBSD by Hiten Pandya <hmp@FreeBSD.org>.

BUGS

     The PCM framework in FreeBSD, as of this writing, does not handle device un-registrations in a properly abstracted manner, i.e., a detach
     request is refused by the PCM framework if the device is in use.  For USB and supposedly other detach-able busses, it is necessary to allow
     the device un-registration to complete successfully, otherwise the driver leaves wild pointers to invalid data structures and thus leading to
     a panic.

BSD
								 December 15, 2005							       BSD