USB: EHCI: add check for wakeup/suspend race

hcd-pci.c in usbcore contains a check for wakeup requests racing with
controller suspend.  This check is going to be moved out of usbcore
and into the individual controller drivers, where it can apply to all
platforms, not just PCI.

This patch adds the check to ehci-hcd.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-hcd.c

@@ -1095,6 +1095,14 @@ int ehci_suspend(struct usb_hcd *hcd, bool do_wakeup)
 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 	spin_unlock_irq(&ehci->lock);
 
+	synchronize_irq(hcd->irq);
+
+	/* Check for race with a wakeup request */
+	if (do_wakeup && HCD_WAKEUP_PENDING(hcd)) {
+		ehci_resume(hcd, false);
+		return -EBUSY;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(ehci_suspend);