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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 number 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 AT FreeBSD DOT 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