System Administration Guide: Basic Administration

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 officially supported. Additionally, keep only one USB keyboard and mouse on the system at all times because multiple USB keyboards and mouse devices 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 USB devices are fully supported on SPARC systems. However, do not suspend a devices that is busy and never remove a device when the system is powered off.

If the SPARC based system has power management enabled, the USB framework makes a best effort to power-manage all devices. Power-managing a USB device means that the hub driver suspends the port to which the device is connected. The device might or might not support remote wakeup. If the device supports remote wakeup, it wakes up the hub it is connected to, depending on the event, such as moving the mouse. The host system could also wake up the device if an application sends an I/O to it.

All HID (keyboard, mouse, speakers, microphones), hub, and storage devices are power-managed by default if they support remote wakeup capability. A USB printer is power-managed only between two print jobs.

When you power-manage to reduce power consumption, USB leaf devices are powered down first, and after some delay, the parent hub is powered down. When all devices that are connected to this 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

Never use USB cable extenders that are available in the market. Always use a hub with longer cables to connect devices. Always use fully rated (12 Mbit/sec) 20/28 AWG cables for connecting USB devices.