Revert "USB: EHCI: don't check DMA values in QH overlays"

This reverts commit 0319f99, which is commit
feca774 upstream.

It shouldn't have gone into this stable release.

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Joseph Salisbury <joseph.salisbury@canonical.com>
Cc: Stephen Thirlwall <sdt@dr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-q.c

@@ -137,7 +137,7 @@ qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
 		 * qtd is updated in qh_completions(). Update the QH
 		 * overlay here.
 		 */
-		if (qh->hw->hw_token & ACTIVE_BIT(ehci)) {
+		if (cpu_to_hc32(ehci, qtd->qtd_dma) == qh->hw->hw_current) {
 			qh->hw->hw_qtd_next = qtd->hw_next;
 			qtd = NULL;
 		}
@@ -450,19 +450,11 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 			else if (last_status == -EINPROGRESS && !urb->unlinked)
 				continue;
 
-			/*
-			 * If this was the active qtd when the qh was unlinked
-			 * and the overlay's token is active, then the overlay
-			 * hasn't been written back to the qtd yet so use its
-			 * token instead of the qtd's.  After the qtd is
-			 * processed and removed, the overlay won't be valid
-			 * any more.
-			 */
-			if (state == QH_STATE_IDLE &&
-					qh->qtd_list.next == &qtd->qtd_list &&
-					(hw->hw_token & ACTIVE_BIT(ehci))) {
+			/* qh unlinked; token in overlay may be most current */
+			if (state == QH_STATE_IDLE
+					&& cpu_to_hc32(ehci, qtd->qtd_dma)
+						== hw->hw_current) {
 				token = hc32_to_cpu(ehci, hw->hw_token);
-				hw->hw_token &= ~ACTIVE_BIT(ehci);
 
 				/* An unlink may leave an incomplete
 				 * async transaction in the TT buffer.