USB_AC(4D) Devices USB_AC(4D)

usb_ac - USB audio control driver


The usb_ac driver is a USBA (Solaris USB Architecture) compliant client driver that supports the USB Audio Class 1.0 specification.

The audio control driver is a USB class driver and offers functionality similar to the audiocs (sun4u) and audiots (Sun Blade 100) drivers which use the Solaris audio mixer framework (mixer(4I)). Unlike the audiocs and audiots drivers, the USB audio device can have play-only or record-only capability.

Drivers corresponding to other USB audio interfaces on the device, including the usb_as(4D) audio streaming driver or the hid(4D) driver, are plumbed under the USB audio control driver and do not directly interface with user applications.

The usb_ac driver supports USB audio class compliant devices with a feature unit.

If a device is hot-removed while it is active, all subsequent opens returns EIO. All other errors are defined in the audio(4I) man page.

32-bit x86 ELF kernel module


64-bit x86 ELF kernel module


64-bit SPARC ELF kernel module.


USB audio driver configuration file.

See attributes(7) for descriptions of the following attributes:

Architecture SPARC, x86, PCI-based systems
Interface Stability Uncommitted

ioctl(2), hid(4D), usb_as(4D), usba(4D), audio(4I), mixer(4I), streamio(4I), usb_ah(4M), attributes(7), cfgadm_usb(8)

Writing Device Drivers

Universal Serial Bus Specification 1.0 and 1.1

Universal Serial Bus Device Class Definition for Audio Devices, Release 1.0

System Administration: Basic Administration

In addition to being logged, the following messages can appear on the system console. All messages are formatted in the following manner:

Warning: <device path> (usb_ac<instance num>): Error Message...

Failure to plumb audio streams drivers.

The usb audio streaming driver or the hid driver could not be plumbed under the audio control driver and the device is not usable.

May 13, 2009 OmniOS