On Sat, Apr 17, 2021 at 02:48:22PM +0800, liulongfang wrote: > On 2021/4/16 23:20, Alan Stern wrote: > > On Fri, Apr 16, 2021 at 10:03:21AM +0800, liulongfang wrote: > >> The current method is an improved method of the above patch. > >> This patch just make it skip registering USB-3 root hub if that hub has no ports, > > > > No, that isn't what this patch does. > > > > If the root hub wasn't registered, hub_probe wouldn't get called. But > > with your patch, the system tries to register the root hub, and it does > > call hub_probe, and then that function fails with a warning message. > > > > The way to _really_ akip registering the root hub is to change the > > xhci-hcd code. Make it skip calling usb_add_hcd. > > > > If you do not register in the root hub, this will return an error code, What will return an error code? Are you talking about xhci_pci_probe()? You oight to be able to figure out how to make it work. > which will make all the XHCI drivers unregister, causing the USB2.0 controllers > on the xhci to be unavailable. Alan Stern
