On Mon, 29 Nov 2010, Sarah Sharp wrote: > This patchset might be better named "xHCI: stop lying and develop a > split personality". > > USB 3.0 external hubs show up as two completely separate devices: a USB > 2.0 hub with LS/FS/HS ports, and a USB 3.0 hub with SS ports. The xHCI > roothub emulation code has always lied to the USB core and created a > single roothub with modified USB 2.0 hub descriptors, that handles ports > of all speeds. With John's patch to add USB 3.0 hub support to the > core, we can finally stop lying and register two xHCI roothubs. > > Alan Stern suggested I register two usb_hcd structures with the USB core > instead of trying to modify all the different HCD's roothub code to > fix the hcd-is-a-bus assumption. I've done that, and probably touched > less code than trying to properly fix that false assumption. > > This is still a WIP, since I haven't addressed the bus and PCI > suspend/resume code yet. I'm considering allowing each bus to suspend > separately (e.g. putting the USB 2.0 ports in suspend, and leaving the > USB 3.0 ports active), but making sure that each bus is suspended before > the whole PCI device is suspended. That's the right way to go. You don't even really need to add the extra check, because the PM core will do it for you. 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
