On Thu, 4 Mar 2010, Crane Cai wrote: > > So a single physical device will show up as two separate devices on the > > same bus? And it will end up getting assigned two separate addresses? > > In that case what I said was correct; the test should be for whether > > the hub is USB 3.0 instead of checking the port speed. That's because, > > as you said, the USB-3.0 incarnation of the hub is SuperSpeed only. > > In our host controller, you will only see one root hub with 4 port, 2 high speed > port and 2 super speed port. When you plug in different device different port > acting. Indeed physical port is only 2. > > In spec, "Figure 40: Port Routing Example" explain it. There is no Figure 40 in the 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. 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
