USB: EHCI: code rearrangement in iso_stream_schedule()

This patch interchanges the "if" and "else" branches of the big "if"
statement in iso_stream_schedule(), in preparation for the next patch
in this series.  That is, it changes

	if (likely(!...)) {
		A
	} else {
		B
	}

to

	if (unlikely(...)) {
		B
	} else {
		A
	}

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

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 85dd24ed97a6d6cf6700405797da29d313e76958..208518bc6e363ce4a9aaaef3604546e105f471eb 100644 (file)
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1384,12 +1384,57 @@ iso_stream_schedule (
 
        now = ehci_read_frame_index(ehci) & (mod - 1);
 
-       /* Typical case: reuse current schedule, stream is still active.
+       /*
+        * Need to schedule; when's the next (u)frame we could start?
+        * This is bigger than ehci->i_thresh allows; scheduling itself
+        * isn't free, the delay should handle reasonably slow cpus.  It
+        * can also help high bandwidth if the dma and irq loads don't
+        * jump until after the queue is primed.
+        */
+       if (unlikely(list_empty(&stream->td_list))) {
+               int done = 0;
+
+               base = now & ~0x07;
+               start = base + SCHEDULING_DELAY;
+
+               /* 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))
+                                       done = 1;
+                       } else {
+                               if ((start % 8) >= 6)
+                                       continue;
+                               if (sitd_slot_ok(ehci, mod, stream,
+                                               start, sched, period))
+                                       done = 1;
+                       }
+               } while (start > next && !done);
+
+               /* no room in the schedule */
+               if (!done) {
+                       ehci_dbg(ehci, "iso sched full %p", urb);
+                       status = -ENOSPC;
+                       goto fail;
+               }
+       }
+
+       /*
+        * Typical case: reuse current schedule, stream is still active.
         * Hopefully there are no gaps from the host falling behind
         * (irq delays etc).  If there are, the behavior depends on
         * whether URB_ISO_ASAP is set.
         */
-       if (likely (!list_empty (&stream->td_list))) {
+       else {
 
                /* Take the isochronous scheduling threshold into account */
                if (ehci->i_thresh)
@@ -1436,49 +1481,6 @@ iso_stream_schedule (
                start += base;
        }
 
-       /* need to schedule; when's the next (u)frame we could start?
-        * this is bigger than ehci->i_thresh allows; scheduling itself
-        * isn't free, the delay should handle reasonably slow cpus.  it
-        * can also help high bandwidth if the dma and irq loads don't
-        * jump until after the queue is primed.
-        */
-       else {
-               int done = 0;
-
-               base = now & ~0x07;
-               start = base + SCHEDULING_DELAY;
-
-               /* 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))
-                                       done = 1;
-                       } else {
-                               if ((start % 8) >= 6)
-                                       continue;
-                               if (sitd_slot_ok(ehci, mod, stream,
-                                               start, sched, period))
-                                       done = 1;
-                       }
-               } while (start > next && !done);
-
-               /* no room in the schedule */
-               if (!done) {
-                       ehci_dbg(ehci, "iso sched full %p", urb);
-                       status = -ENOSPC;
-                       goto fail;
-               }
-       }
-
        /* Tried to schedule too far into the future? */
        if (unlikely(start - base + span - period >= mod)) {
                ehci_dbg(ehci, "request %p would overflow (%u+%u >= %u)\n",