USB: EHCI: expedite unlinks when the root hub is suspended

This patch (as1225) fixes a bug in ehci-hcd.  The condition for
whether unlinked QHs can become IDLE should not be that the controller
is halted, but rather that the controller isn't running.  In other
words when the root hub is suspended, the hardware doesn't own any
QHs.

This fixes a problem that can show up during hibernation: If a QH is
only partially unlinked when the root hub is frozen, then when the
root hub is thawed the QH won't be in the IDLE state.  As a result it
can't be used properly for new URB submissions.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Brandon Philips <brandon@ifup.org>
Tested-by: Brandon Philips <brandon@ifup.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 3712b925b315..ecc9b66c03cd 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -1095,7 +1095,8 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
         prev->qh_next = qh->qh_next;
         wmb ();
 
-        if (unlikely (ehci_to_hcd(ehci)->state == HC_STATE_HALT)) {
+        /* If the controller isn't running, we don't have to wait for it */
+        if (unlikely(!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))) {
                 /* if (unlikely (qh->reclaim != 0))
                  *      this will recurse, probably not much
                  */