---
name: "snd_uaudio"
section: "4"
platform: "linux"
package: "freebsd-manpages"
version: "6.0-5"
release: "Debian 4.0 (Etch)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/snd_uaudio"
---

# snd\_uaudio(4)

USB audio device driver

## NAME

**snd\_uaudio** – USB audio device driver

## SYNOPSIS

**device sound** **device usb** **device snd\_uaudio**

## 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)](/sound/4.md), [usb(4)](/usb/4.md) *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.