1 files changed, 14 insertions, 8 deletions

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 2e829fae6482..a60679cbbf85 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1475,30 +1475,36 @@ iso_stream_schedule (
          * jump until after the queue is primed.
          */
         else {
+                int done = 0;
                 start = SCHEDULE_SLOP + (now & ~0x07);
 
                 /* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
 
-                /* find a uframe slot with enough bandwidth */
-                next = start + period;
-                for (; start < next; start++) {
-
+                /* find a uframe slot with enough bandwidth.
+                 * Early uframes are more precious because full-speed
+                 * iso IN transfers can't use late uframes,
+                 * and therefore they should be allocated last.
+                 */
+                next = start;
+                start += period;
+                do {
+                        start--;
                         /* check schedule: enough space? */
                         if (stream->highspeed) {
                                 if (itd_slot_ok(ehci, mod, start,
                                                 stream->usecs, period))
-                                        break;
+                                        done = 1;
                         } else {
                                 if ((start % 8) >= 6)
                                         continue;
                                 if (sitd_slot_ok(ehci, mod, stream,
                                                 start, sched, period))
-                                        break;
+                                        done = 1;
                         }
-                }
+                } while (start > next && !done);
 
                 /* no room in the schedule */
-                if (start == next) {
+                if (!done) {
                         ehci_dbg(ehci, "iso resched full %p (now %d max %d)\n",
                                 urb, now, now + mod);
                         status = -ENOSPC;