A USB device configuration defines how a device presents itself to the operating system. USB device configuration differs from system device configurations that use the cfgadm command and which are discussed in other sections in this book.
Some USB devices support multiple configurations. However, only one configuration can be active at a time. You can identify devices with multi-configurations by using the cfgadm –lv command. From the command output, two parameters provide multi-configuration information:
Nconfigs indicates the number of configurations for the device.
Config indicates the configuration that is currently active and is therefore the default configuration.
Changes to the default configuration persist across reboots, hot-removes, and the reconfiguration of the device, provided that the device is reconnected to the same port.
# cfgadm -lv [device]
You can specify the device if you already know the Ap_Id whose default configuration you are changing.
Ensure that you also confirm the action at the prompt.
# cfgadm -x usb_config -o config=config-number device
The following example changes the configuration of usb0/4 from 1 to 2.
# cfgadm -x usb_config -o config=2 usb0/4 Setting the device: /devices/pci@1f,0/usb@c,3:4 to USB configuration 2 This operation will suspend activity on the USB device Continue (yes/no)? yes
# cfgadm -lv device
The following example shows the changes for usb0/4 after the previous step.
# cfgadm -lv usb0/4 Ap_Id Receptacle Occupant Condition Information When Type Busy Phys_Id usb0/4 connected unconfigured ok Mfg: Sun 2000 Product: USB-B0B0 aka Robotech With 6 EPPS High Clk Mode NConfigs: 7 Config: 2 :Default configuration is now 2. EVAL Board Setup unavailable usb-device n /devices/pci@1f,0/usb@c,3:4