USB 2.0 Device Features and Compatibility Issues (System Administration Guide: Devices and File Systems)

System Administration Guide: Devices and File Systems

USB 2.0 Device Features and Compatibility Issues

USB 2.0 devices are defined as high-speed devices that follow the USB 2.0 specification. You can refer to the USB 2.0 specification at http://www.usb.org.

To identify the speed of your USB device in the Solaris 10 releases, check the /var/adm/messages file for messages similar to the following:

Dec 13 17:05:57 mysystem usba: [ID 912658 kern.info] USB 2.0 device
(usb50d,249) operating at hi speed (USB 2.x) on USB 2.0 external hub:
storage@4, scsa2usb0 at bus address 4

Here are some of the USB devices that are supported in this Solaris release:

Mass storage devices, such as CD-RWs, hard disks, DVDs, digital cameras, diskettes, tape drives, memory sticks, and multi-format card readers
Keyboards and mouse devices
Audio devices, such as speakers and microphones

For a full listing of USB devices that have been verified on the Solaris release, go to:

http://www.sun.com/io_technologies/USB.html

Additional storage devices might work by modifying the scsa2usb.conf file. For more information, see scsa2usb(7D).

Solaris USB 2.0 device support includes the following features:

Increased USB bus speed from 12 Mbyte/sec to 480 Mbyte/sec. This increase means devices that support the USB 2.0 specification can run significantly faster than their USB 1.1 counterparts, when they are connected to a USB 2.0 port.

A USB 2.0 port might be one of the following possibilities:
- A port on a USB 2.0 PCI card
- A port on a USB 2.0 hub that is connected to USB 2.0 port
- A port on a SPARC or x86 computer motherboard
A USB 2.0 PCI card might be needed for older SPARC platforms.
For a list of USB 2.0 PCI cards that have been verified for the Solaris release, go to:

http://www.sun.com/io_technologies/USB.html
USB 1.1 devices work as they have in the past, even if you have both USB 1.1 and USB 2.0 devices on the same system.
While USB 2.0 devices operate on a USB 1.x port, their performance is significantly better when they are connected to a USB 2.0 port.
A USB 2.0 host controller has one high-speed Enhanced Host Controller Interface (EHCI) and one or more OpenHCI Host Controller Interface (OHCI) or Universal Host Controller Interface (UHCI) embedded controllers. Devices connected to a USB 2.0 port are dynamically assigned to either an EHCI or OHCI controller, depending on whether they support USB 2.0.

Note –
USB 2.0 storage devices that are connected to a port on a USB 2.0 PCI card, and that were used with a prior Solaris release in the same hardware configuration, can change device names after upgrading to this release. This change occurs because these devices are now seen as USB 2.0 devices and are taken over by the EHCI controller. The controller number, w in /dev/[r]dsk/cwtxdysz, is changed for these devices.

Also note that the speed of a USB device is limited to what the parent port can support. For example, if a USB 2.0 external hub is followed by a USB 1.x hub and a USB 2.0 device downstream, devices that are connected to the USB 2.0 external hub run at full speed and not high speed.

For more information on USB 2.0 device support, see ehci(7D) and usba(7D).