I've been having some problems with the EHCI driver on my Thinkpad T40,
running 2.6.9 with APM instead of ACPI.  On resume after suspend-to-RAM
the EHCI hardware keeps the interrupt line high, but the EHCI driver is
not clearing the interrupt status register, causing Linux to eventually
disable the interrupt altogether.

The attached patch for ehci-hub.c does the obvious thing: delay enabling
interrupts until hcd->state is set to USB_STATE_RUNNING.

From: Nickolai Zeldovich <nickolai@cs.stanford.edu>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>