On Thu, Mar 04, 2010 at 10:00:50AM -0500, Alan Stern wrote: > > In spec, "Figure 40: Port Routing Example" explain it. > > There is no Figure 40 in the USB-3.0 spec. It is in xHCI spec, not USB-3.0 spec. > Instead, the spec says: > > The root ports of a USB 3.0 host have similar functional > requirements to the downstream ports of a USB 3.0 hub. > > Interpreted in the most literal sense, this means that a USB-3.0 > controller must have _two_ root hubs: one for the SuperSpeed controller > and one for the high/full/low-speed controller. Not one hub with two > separate-but-parallel sets of ports. In a USB3 hub, two independently addressable hub ports exist for each physical down stream connector; a USB2 compatible port accessed through the High-speedUSB2 connection and a USB3 compatible port accessed through the SuperSpeed connection. The Root Hub of the xHCI emulates this operation by defining a Root Hub PORTSC register for each connection type; USB2 (Low-/Full-/High-Speed) or USB3 (SuperSpeed). Suppose this words make it clear. -- Best Regards, - Crane -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
