one OHCI companion controller, and only one USB 2.0 Host port. All ports on an USB 2.0 controller default to the companion controller. If you load only an ohci driver, it will have control of the ports and any deviceplugged in will operate, although high speed devices will be forced to operate at full speed. When an ehci driver is loaded, it explicitly takes control of the ports. If there is a device connected, and / or every time there is a new device connected, the ehci driver determines if the device is high speed or not. If it is high speed, the driver retains control of the port. If it is not, the driver explicitly gives the companion controller control of the port. The is a software workaround that uses Initial version of the software workaround was posted to linux-usb-devel: http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg54019.html and later available from amcc.com: http://www.amcc.com/Embedded/Downloads/download.html?cat=1&family=15&ins=2 The patch below is generally based on the latter, but reworked to powerpc/of_device USB drivers, and uses a few devicetree inquiries to get rid of (some) hardcoded defines. Signed-off-by: Vitaly Bordug Signed-off-by: Stefan Roese Cc: David Brownell Signed-off-by: Greg Kroah-Hartman I(y0x