drivers/usb/host/ehci-sched.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

Index: usb-3.11/drivers/usb/host/ehci-sched.c
===================================================================
--- usb-3.11.orig/drivers/usb/host/ehci-sched.c
+++ usb-3.11/drivers/usb/host/ehci-sched.c
@@ -1391,21 +1391,20 @@ iso_stream_schedule (
 
 		/* Behind the scheduling threshold? */
 		if (unlikely(start < next)) {
+			unsigned now2 = (now - base) & (mod - 1);
 
 			/* USB_ISO_ASAP: Round up to the first available slot */
 			if (urb->transfer_flags & URB_ISO_ASAP)
 				start += (next - start + period - 1) & -period;
 
 			/*
-			 * Not ASAP: Use the next slot in the stream.  If
-			 * the entire URB falls before the threshold, fail.
+			 * Not ASAP: Use the next slot in the stream,
+			 * no matter what.
 			 */
-			else if (start + span - period < next) {
-				ehci_dbg(ehci, "iso urb late %p (%u+%u < %u)\n",
+			else if (start + span - period < now2) {
+				ehci_warn(ehci, "iso underrun %p (%u+%u < %u)\n",
 						urb, start + base,
-						span - period, next + base);
-				status = -EXDEV;
-				goto fail;
+						span - period, now2 + base);
 			}
 		}