1.\" $NetBSD: uaudio.4,v 1.15 2002/02/12 19:53:57 jdolecek Exp $ 2.\" 3.\" Copyright (c) 1999 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Lennart Augustsson. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.\" $FreeBSD: src/share/man/man4/snd_uaudio.4,v 1.5.4.1 2006/01/09 12:48:39 joel Exp $ 38.\" $DragonFly: src/share/man/man4/snd_uaudio.4,v 1.2 2007/06/16 17:44:34 hasso Exp $ 39.\" 40.Dd December 15, 2005 41.Dt SND_UAUDIO 4 42.Os 43.Sh NAME 44.Nm snd_uaudio 45.Nd USB audio device driver 46.Sh SYNOPSIS 47To compile this driver into the kernel, place the following lines in your 48kernel configuration file: 49.Bd -ragged -offset indent 50.Cd "device pcm" 51.Cd "device usb" 52.Cd "device snd_uaudio" 53.Ed 54.Pp 55Alternatively, to load the driver as a module at boot time, place the 56following line in 57.Xr loader.conf 5 : 58.Bd -literal -offset indent 59snd_uaudio_load="YES" 60.Ed 61.Sh DESCRIPTION 62The 63.Nm 64driver provides support for 65.Tn USB 66audio class devices. 67.Pp 68A 69.Tn USB 70audio device consists of a number of components: 71input terminals (e.g.\& USB digital input), output terminals (e.g.\& 72speakers), and a number of units in between (e.g.\& volume control). 73.Pp 74Refer to the 75.Ql USB Audio Class Specification 76for more information. 77.Sh SEE ALSO 78.Xr sound 4 , 79.Xr usb 4 80.Rs 81.%T "USB Audio Class Specifications" 82.%O http://www.usb.org/developers/devclass_docs/ 83.Re 84.Sh HISTORY 85The 86.Nm 87driver first appeared in 88.Fx 4.7 . 89.Sh AUTHORS 90This manual page was adopted from 91.Nx 1.6 92and modified for 93.Fx 94by 95.An Hiten Pandya Aq hmp@FreeBSD.org . 96.Sh BUGS 97The 98.Tn PCM 99framework in 100.Fx , 101as of this writing, does not handle device un-registrations in a properly 102abstracted manner, i.e., a detach request is refused by the 103.Tn PCM 104framework if the device is in use. 105For 106.Tn USB 107and supposedly other detach-able busses, it is necessary to allow the 108device un-registration to complete successfully, otherwise the driver 109leaves wild pointers to invalid data structures and thus leading to a panic. 110