System Administration Guide: Devices and File Systems

About USB in the Solaris Environment

This section describes information you should know about USB in the Solaris environment.

USB Keyboards and Mouse Devices

Only Sun USB keyboards and mouse devices are supported. System configurations with multiple USB keyboards and mouse devices might work, but are not supported in the Solaris environment. See the following items for details.

USB Host Controller and Root Hub

A USB hub is responsible for the following:

The USB host controller has an embedded hub called the root hub. The ports that are visible at the system's back panel are the ports of the root hub. The USB host controller is responsible for the following:

USB Hub Devices

SPARC: USB Power Management

Suspending and resuming of USB devices is fully supported on SPARC systems. However, do not suspend a device that is busy and never remove a device when the system is powered off under a suspend shutdown.

The USB framework makes a best effort to power manage all devices on SPARC-based systems with power management enabled. Power managing a USB device means that the hub driver suspends the port to which the device is connected. Devices that support remote wake up can notify the system to wake up everything in the device's path, so that the device can be used. The host system could also wake up the device if an application sends an I/O to the device.

All HID (keyboard, mouse, speakers, microphones), hub, and storage devices are power-managed by default if they support remote wake up capability. A USB printer is power-managed only between two print jobs. Devices that are directed by the generic USB driver (UGEN) are power managed only when they are closed.

When power management is running to reduce power consumption, USB leaf devices are powered down first. After all devices that are connected to a hub's ports are powered down, the hub is powered down after some delay. To achieve the most efficient power management, do not cascade many hubs.

Guidelines for USB Cables

Keep the following guidelines in mind when connecting USB cables:

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