uaudio -- USB audio device driver
device pcm
device usb
The 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.
pcm(4), usb(4)
USB Audio Class Specifications,
http://www.usb.org/developers/devclass_docs/.
The uaudio driver first appeared in appeared in FreeBSD 4.7.
This manual page was adopted from NetBSD 1.6 and modified for FreeBSD by
Hiten Pandya <hmp@FreeBSD.org>.
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.
FreeBSD 5.2.1 November 10, 2003 FreeBSD 5.2.1 [ Back ] |