On Mon, 24 Dec 2012, Larry Finger wrote:
The problem has been bisected to commit adfa79d entitled "USB: EHCI: make
ehci-pci a separate driver". The symptom is that my NVIDIA controller again
reverts to unended logging of messages of the form "hub 2-0:1.0: unable to
enumerate USB device on port 5".
A few more details would be helpful, such as the dmesg log (with
CONFIG_USB_DEBUG enabled). As it is, I don't see how that commit could
cause this problem. It should not have resulted in any changes in
behavior -- all it did was split up a driver that was one module into
two modules.
This behavior was previously fixed with commit c618759.
That commit affected the ohci-hcd driver, whereas this one affects
ehci-hcd. They can't possibly be related.