On Sun, 26 Aug 2012, Lan Tianyu wrote: > � 2012/8/24 22:45, Alan Stern � > > On Fri, 24 Aug 2012, Lan Tianyu wrote: > > > >>>> But if other places got hub descriptor, they can't get DeviceRemovable > >>>> value since we only set DeviceRemovable in the hub_configure().(e.g lsusb). > > > > Note: This isn't true. You now set desc->u.hs.DeviceRemovable in > > ehci_hub_descriptor(). > Oh. Sorry. I maybe confuse you or make you misunderstand due to my broken > descriptor. Do you agree set desc->u.hs.DeviceRemovable in ehci_hub_descriptor()? Yes. Ideally, those bits should be set even if the hub driver isn't bound to the root hub device. > At the first time, the hub->maxchild is not set and port's device was not > created so usb port has not been bound with acpi. usb port's ACPI information is > not accessible at that time. The usb_get_hub_port_connect_type will return > type_unkown. > The value returned by first time of call get_hub_descriptor() will not be correct. Now I see the problem. The code you're adding to ehci-hub.c relies on the hub driver knowing about the root hub's ports beforehand. So you've got a circular dependency: ehci-hub.c depends on the hub driver knowing about the root hub's ports; The hub driver learns the root-hub port connectivity information by asking ehci-hub.c. The way to break this circle is to make ehci-hub.c use the ACPI information directly rather than going through the hub driver's data structures. 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
