Hot-Plugging USB Devices With the cfgadm Command (Task Map)
Hot-Plugging USB Devices With the cfgadm Command
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.
Receptacle State |
Description |
empty/unconfigured |
The device is
not physically connected. |
disconnected/unconfigured |
The device is logically disconnected and unavailable, even though the device
could still be physically connected. |
connected/unconfigured |
The device is logically connected, but unavailable. The
device is visible in prtconf output. |
connected/configured |
The device is connected and available. |
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.
- 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.
- 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.
- Become superuser.
- 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
- 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
- Become superuser.
- Configure a USB device.
For example:
# cfgadm -c configure usb0/4.7
- 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.
- Become superuser.
- Disconnect a USB device.
For example:
# cfgadm -c disconnect -y usb0/4.7
- 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.
- Become superuser.
- Connect a USB device.
For example:
# cfgadm -c configure usb0/4.7
- 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.
- Become superuser.
- Remove a USB device subtree.
For example:
# cfgadm -c disconnect -y usb0/4
- 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 re-creates the device.
- Become superuser.
- Make sure that the device is not in use.
- Reset the device.
For example:
# cfgadm -x usb_reset -y usb0/4.7
- 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.
- Make sure that the device is not in use.
- 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
- 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.