On Fri, 5 Mar 2010, Crane Cai wrote: > 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. That doesn't do me any good, since I don't have access to the xHCI spec. > 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). That is not a correct emulation. A correct emulation would define two root hubs, with two different device descriptors. Not just two PORTSC registers for each port. Alan Stern -- 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
