diff --git a/share/man/man4/snd_uaudio.4 b/share/man/man4/snd_uaudio.4 --- a/share/man/man4/snd_uaudio.4 +++ b/share/man/man4/snd_uaudio.4 @@ -27,7 +27,7 @@ .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" -.Dd November 12, 2016 +.Dd January 29, 2024 .Dt SND_UAUDIO 4 .Os .Sh NAME @@ -51,24 +51,74 @@ .Sh DESCRIPTION The .Nm -driver provides support for -.Tn USB -audio class devices and -.Tn USB -MIDI class devices. +driver provides support for USB audio class devices and USB MIDI class devices. .Pp -A -.Tn 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). +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). .Pp Refer to the .Ql USB Audio Class Specification for more information. +.Ss Runtime Configuration +.Nm +provides the following +.Xr sysctl 8 +variables which can be modified during runtime: +.Bl -tag -width indent +.It Va hw.usb.uaudio.buffer_ms +Buffering delay in milliseconds, from 1 to 8 (default is 4). +Because this value is set during boot-time. +In order for a change in this value to take effect, one has to either set +.Va hw.usb.uaudio.buffer_ms +in +.Pa /boot/loader.conf +and reboot, or set it through +.Xr sysctl 8 , +and re-attach the device. +.It Va hw.usb.uaudio.default_bits +Default sample bits, from 0 to 32 (default is 32). +.It Va hw.usb.uaudio.default_channels +Default sample channels, from 0 to +.Pa UAUDIO_CHANNELS_MAX +(default is 0). If set to 0, the channels +will be either 4 for USB devices running in full-speed mode, or +.Pa UAUDIO_CHANNELS_MAX . +.Pp +.Pa UAUDIO_CHANNELS_MAX +is defined as the minimum value between 64 and the highest supported channel +number (see +.Pa AFMT_CHANNEL_MAX ) . +.It Va hw.usb.uaudio.default_rate +Default sample rate. +If set to 0, the device's defaults will be used. +.It Va hw.usb.uaudio.handle_hid +Let +.Nm +handle HID volume keys, if any (default is 1). +.Bl -tag -width 2n +.It 0 +Disabled. +.It 1 +Enabled. +.El +.El +.Pp +If +.Xr usb 4 +has been compiled with +.Va USB_DEBUG +on, the following +.Xr sysctl 8 +variable is also available: +.Bl -tag -width indent +.It Va hw.usb.uaudio.debug +Debug output level (default is 0). +.El .Sh SEE ALSO .Xr sound 4 , -.Xr usb 4 +.Xr usb 4 , +.Xr sysctl 8 .Rs .%T "USB Audio Class Specifications" .%U http://www.usb.org/developers/docs/devclass_docs/ @@ -86,9 +136,7 @@ by .An Hiten Pandya Aq Mt hmp@FreeBSD.org . .Sh BUGS -The -.Tn PCM -framework in +The PCM framework in .Fx only supports synchronous device detach. That means all mixer and DSP character devices belonging to a given @@ -104,9 +152,7 @@ .Va dev.pcm.%d.[play|rec].vchanrate sysctls. .Pp -The -.Tn PCM -framework in +The PCM framework in .Fx currently doesn't support the full set of USB audio mixer controls.