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     snd_uaudio — USB audio device driver


     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):



     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.


     sound(4), usb(4)

     USB Audio Class Specifications,


     The snd_uaudio driver first appeared in FreeBSD 4.7.


     This manual page was adopted from NetBSD 1.6 and modified for FreeBSD by
     Hiten Pandya ⟨⟩.


     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.