USB Hub Devices

• Do not cascade hubs beyond four levels on either SPARC based or x86 based systems. On SPARC systems, the OpenBoot™ PROM cannot reliably probe beyond four levels of devices.

• Do not plug a bus-powered hub into another bus-powered hub in a cascading style. A bus-powered hub does not have its own power supply.

• Do not connect a device that requires a large amount of power to a bus-powered hub. These devices might not work well on bus-powered hubs or might drain the hub of power for other devices. An example of such a device is a USB diskette device.

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:

• Always use USB 2.0 compliant, fully rated (480 Mbit/sec) 20/28 AWG cables for connecting USB 2.0 devices.

• Always use USB 1.0 compliant, fully rated (12 Mbit/sec) 20/28 AWG cables for connecting USB 1.0 or 1.1 devices. Use bus-powered hubs for low-speed devices only. Always use fully rated (12 Mbit/sec) 20/28 AWG cables for connecting USB devices.

• Maximum cable length that is supported is 5 meters.

• Do not use cable extenders. For best results, use a self-powered hub to extend cable length.

For more information, go to http://www.usb.org/channel/training/warning.

Managing USB Devices in the Solaris Environment (Roadmap)

Use this map to identify all the tasks for managing USB devices in the Solaris environment. Each task points to a series of additional tasks such as using USB devices, hot-plugging USB devices, or adding USB audio devices.

Using USB Mass Storage Devices (Task Map)

Using USB Mass Storage Devices

Note - For up-to-date information on using USB mass storage devices in this Solaris release, see USB Mass Storage Devices.

Starting in the Solaris 9 4/04 release, removable mass storage devices such as USB CD-RWs, hards disks, DVDs, digital cameras, Zip, Peerless, SmartMedia, CompactFlash, ORB, and USB diskette devices are supported by ports operated by the USBA 1.0 framework.

An easy way to find out which framework is operating your device is to use the prtconf -D command before and after plugging in your device. By using this method, you'll find your device in the latter output. The USBA 1.0 framework is operating your device if the prtconf entry above it says usba10_scsa2usb. scsa2usb implies the original framework.

For a complete list of USB devices that are supported in the Solaris environment, see http://www.sun.com/io_technologies/USB.html.

These devices can be managed with or without volume management. For information on managing devices with volume management, see vold(1M).

Using USB Diskette Devices

USB diskette devices appear as removable media devices like other USB devices. USB diskette devices are not managed by the fd (floppy) driver. Applications that issue ioctl(2) calls intended for the fd (native floppy) driver will fail. Applications that issue only read(2) and write(2) calls will succeed. Other applications, such as SunPCI and rmformat, will also succeed.

Note - CDE's File Manager does not fully support USB diskettes at this time. However, you can open, rename, and format diskettes that contain a UFS file system from File Manager's Removable Media Manager. You can only open diskettes that contain a PCFS file system from the Removable Media Manager. If a diskette contains either type of file system, you can successfully drag and drop files between the diskette and File Manager.

Volume management (vold) sees the USB diskette device as a SCSI removable media device. Volume management makes the device available for access under the /rmdisk directory.

For more information on how to use USB diskette devices, see Chapter 17, Managing Removable Media (Overview).

Using Non-Compliant USB Mass Storage Devices

Some devices might be supported by the USB mass storage driver even though they do not identify themselves as compliant with the USB mass storage class or identify themselves incorrectly. The scsa2usb.conf file contains an attribute-override-list that lists the vendor ID, product ID, and revision for matching mass storage devices, as well as fields for overriding the default device attributes. The entries in this list are commented out by default, and can be copied and uncommented to enable support of particular devices.

If you connect a USB mass storage device to a system running this Solaris release and the system is unable to use it, you can check the /kernel/drv/scsa2usb.conf file to see if there is a matching, commented entry for this device. Follow the information given in the scsa2usb.conf file to see if a particular device can be supported by using the override information. For a listing of recommended USB mass storage devices, go to http://www.sun.com/io_technologies/USB.html.

For more information, see scsa2usb(7D).

Preparing to Use a USB Mass Storage Device With vold Running

If you are running the Solaris Common Desktop Environment (CDE), USB removable mass storage devices are managed by the Removable Media Manager component of the CDE File Manager. For more information on the CDE File Manager, see dtfile(1).

Note - You must include the /usr/dt/man directory in your MANPATH variable to display the man pages that are listed in this section. You must also have the /usr/dt/bin directory in your path and have CDE running to use these commands, or have a DISPLAY variable set to use these commands remotely.

The following table identifies the commands that Removable Media Manager uses to manage storage devices from the CDE environment.

After the USB device is formatted, it is usually mounted under the /rmdisk/label directory. For more information on configuring removable storage devices, see rmmount.conf(4) or vold.conf(4).

The device nodes are created under the /vol/dev directory. For more information, see scsa2usb(7D).

The following procedures describe how to manage USB mass storage devices without vold running. The device nodes are created under the /dev/rdsk directory for character devices and under the /dev/dsk directory for block devices. Device links are created when the devices are hot-plugged. For more information, see scsa2usb(7D).