USB: EHCI: resolve some unlikely races

This patch (as1589) resolves some unlikely races involving system
shutdown or controller death in ehci-hcd:

	Shutdown races with both root-hub resume and controller
	resume.

	Controller death races with root-hub suspend.

A new bitflag is added to indicate that the controller has been shut
down (whether for system shutdown or because it died).  Tests are
added in the suspend and resume pathways to avoid reactivating the
controller after any sort of shutdown.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 7de58fe52d5..da07d98f7d1 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -118,6 +118,7 @@ struct ehci_hcd {			/* one per controller */
         bool                    need_rescan:1;
         bool                    intr_unlinking:1;
         bool                    async_unlinking:1;
+        bool                    shutdown:1;
         struct ehci_qh          *qh_scan_next;
 
         /* async schedule support */