Hot-Plugging USB Devices With the cfgadm Command

The following tasks are provided in this section:

• How to Display USB Bus Information (cfgadm)

• How to Unconfigure a USB Device

• How to Configure a USB Device

• How to Logically Disconnect a USB Device

• How to Logically Connect a USB Device

• How to Logically Disconnect a USB Device Subtree

• How to Reset a USB Device

• How to Change the Default Configuration of a Multi-Configuration USB Device

You can add and remove a USB device from a running system without using the cfgadm command. However, a USB device can also be logically hot-plugged without physically removing the device. This scenario is convenient when you are working remotely and you need to disable or reset a non functioning USB device. The cfgadm command also provides a way to display the USB device tree, including manufacturer and product information.

The cfgadm command displays information about attachment points, which are locations in the system where dynamic reconfiguration operations can occur.

An attachment point consists of the following:

• An occupant, which represents a hardware resource, such as a USB device, that might be configured into the system

• A receptacle, which is the location that accepts the occupant, such as a USB port

Attachment points are represented by logical and physical attachment point IDs (Ap_Ids). The physical Ap_Id is the physical path name of the attachment point. The logical Ap_Id is a user-friendly alternative for the physical Ap_Id. For more information on Ap_Ids, see cfgadm_usb(1M).

The cfgadm command provides the following USB device status information.

The following sections describe how to hot-plug a USB device through the software with the cfgadm command. All of the sample USB device information in these sections has been truncated to focus on relevant information.

How to Display USB Bus Information (cfgadm)

For examples of using the prtconf command to display USB configuration information, see How to Display USB Device Information.

1. Display USB bus information.

   For example:

   $ cfgadm
   Ap_Id                    Type         Receptacle   Occupant     Condition
   usb0/4.5                 usb-hub      connected    configured   ok
   usb0/4.5.1               usb-device   connected    configured   ok
   usb0/4.5.2               usb-printer  connected    configured   ok
   usb0/4.5.3               usb-mouse    connected    configured   ok
   usb0/4.5.4               usb-device   connected    configured   ok
   usb0/4.5.5               usb-storage  connected    configured   ok
   usb0/4.5.6               usb-communi  connected    configured   ok
   usb0/4.5.7               unknown      empty        unconfigured ok

   In the preceding example, usb0/4.5.1 identifies a device connected to port 1 of the second-level external hub, which is connected to port 5 of first-level external hub, which is connected to the first USB controller's root hub, port 4.

2. Display specific USB device information.

   For example:

   $ cfgadm -l -s "cols=ap_id:info"
   Ap_Id       Information
    usb0/4.5.1  Mfg: Inside Out Networks Product: Edgeport/421 NConfigs: 1 
   Config: 0  : ...
    usb0/4.5.2  Mfg: <undef> Product: <undef>   NConfigs: 1 Config: 0 ...
    usb0/4.5.3  Mfg: Mitsumi Product: Apple USB Mouse NConfigs: 1
   Config: 0 ...
    usb0/4.5.4  Mfg: NMB  Product: NMB USB KB/PS2 M NConfigs: 1 Config: 0
    usb0/4.5.5  Mfg: Hagiwara Sys-Com  Product: SmartMedia R/W  NConfigs: 1 
   Config: 0 : ...
    usb0/4.5.6  Mfg: 3Com Inc.  Product: U.S.Robotics 56000 Voice USB Modem 
   NConfigs: 2 ...
    usb0/4.5.7

How to Unconfigure a USB Device

You can unconfigure a USB device that is still physically connected to the system. However, a driver will never attach to the device. Note that a USB device remains in the prtconf output even after that device is unconfigured.

1. Become an administrator.
2. Unconfigure the USB device.

   For example:

   # cfgadm -c unconfigure usb0/4.7
   Unconfigure the device: /devices/pci@8,700000/usb@5,3/hub@4:4.7
   This operation will suspend activity on the USB device
   Continue (yes/no)? y

3. Verify that the device is unconfigured.

   For example:

   # cfgadm  
   Ap_Id                    Type         Receptacle   Occupant     Condition
   usb0/4.5                 usb-hub      connected    configured   ok
   usb0/4.5.1               usb-device   connected    configured   ok
   usb0/4.5.2               usb-printer  connected    configured   ok
   usb0/4.5.3               usb-mouse    connected    configured   ok
   usb0/4.5.4               usb-device   connected    configured   ok
   usb0/4.5.5               usb-storage  connected    configured   ok
   usb0/4.5.6               usb-communi  connected    configured   ok
   usb0/4.5.7               unknown      empty        unconfigured ok
   usb0/4.6                 usb-storage  connected    configured   ok
   usb0/4.7                 usb-storage  connected    unconfigured ok

How to Configure a USB Device

1. Become an administrator.
2. Configure a USB device.

   For example:

   # cfgadm -c configure usb0/4.7 

3. Verify that the USB device is configured.

   For example:

   # cfgadm usb0/4.7
   Ap_Id                  Type         Receptacle  Occupant    Condition
   usb0/4.7               usb-storage  connected   configured  ok

How to Logically Disconnect a USB Device

If you want to remove a USB device from the system and the prtconf output, but you are not physically near the system, just logically disconnect the USB device. The device is still physically connected. However, the device is logically disconnected, unusable, and not visible to the system.

1. Become an administrator.
2. Disconnect a USB device.

   For example:

   # cfgadm -c disconnect -y usb0/4.7

3. Verify that the device is disconnected.

   For example:

   # cfgadm usb0/4.7
   Ap_Id                  Type      Receptacle    Occupant      Condition
   usb0/4.7               unknown   disconnected  unconfigured  ok

How to Logically Connect a USB Device

Use this procedure to logically connect a USB device that was previously logically disconnected or unconfigured.

1. Become an administrator.
2. Connect a USB device.

   For example:

   # cfgadm -c configure usb0/4.7

3. Verify that the device is connected.

   For example:

   # cfgadm usb0/4.7
   Ap_Id                  Type         Receptacle  Occupant    Condition
   usb0/4.7               usb-storage  connected   configured  ok

   The device is now available and visible to the system.

How to Logically Disconnect a USB Device Subtree

Use this procedure to disconnect a USB device subtree, which is the hierarchy (or tree) of devices below a hub.

1. Become an administrator.
2. Remove a USB device subtree.

   For example:

   # cfgadm -c disconnect -y usb0/4

3. Verify that the USB device subtree is disconnected.

   For example:

   # cfgadm usb0/4
   Ap_Id                  Type       Receptacle   Occupant     Condition
   usb0/4                 unknown    disconnected unconfigured ok

How to Reset a USB Device

If a USB device behaves erratically, use the cfgadm command to reset the device, which logically removes and recreates the device.

1. Become an administrator.
2. Make sure that the device is not in use.
3. Reset the device.

   For example:

   # cfgadm -x usb_reset -y usb0/4.7

4. Verify that the device is connected.

   For example:

   # cfgadm usb0/4.7
   Ap_Id                  Type         Receptacle   Occupant     Condition
   usb0/4.7               usb-storage  connected    configured   ok

How to Change the Default Configuration of a Multi-Configuration USB Device

Keep the following in mind when working with multi-configuration USB devices:

• A USB device configuration defines how a device presents itself to the operating system. This method is different from system device configurations discussed in other cfgadm sections.

• Some USB devices support multiple configurations, but only one configuration can be active at a time.

• Multi-configuration devices can be identified by examining the cfgadm -lv output. Nconfigs will be greater than 1.

• The default USB configuration is configuration 1. The current configuration is reflected in cfgadm -lv output as Config.

• Changes to the default configuration persist across reboots, hot-removes, and the reconfiguration of the device, as long as the device is reconnected to the same port.

1. Make sure that the device is not in use.
2. Change the default USB configuration.

   For example:

   # 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

3. Verify that the device changed.

   For example:

   # 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  : EVAL Board Setup  
   unavailable
   usb-device   n        /devices/pci@1f,0/usb@c,3:4

   Note that Config: now shows 2.