[56/80] EHCI : Fix a regression in the ISO scheduler

Greg KH
2011-12-07T16:20:07Z

From: Matthieu CASTET <castet.matthieu@free.fr>

commit e3420901eba65b1c46bed86d360e3a8685d20734 upstream.

Fix a regression that was introduced by commit
811c926c538f7e8d3c08b630dd5844efd7e000f6 (USB: EHCI: fix HUB TT scheduling
issue with iso transfer).

We detect an error if next == start, but this means uframe 0 can't be allocated
anymore for iso transfer...

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/usb/host/ehci-sched.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1479,6 +1479,7 @@ 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 */
@@ -1496,18 +1497,18 @@ iso_stream_schedule (
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);
+ } 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;