USB: EHCI: No SSPLIT allowed in uframe 7

The scheduling code in ehci-hcd contains an error.  For full-speed
isochronous-OUT transfers, the EHCI spec forbids scheduling
Start-Split transactions in H-microframe 7, but the driver allows it
anyway.  This patch adds a check to prevent it.

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 4b0903c6c616b6c2088db8221a4c94136aa978fc..1fc2befc4fdc1d6d8a82b045702b8e9678bb656d 100644 (file)
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1286,6 +1286,10 @@ sitd_slot_ok (
 
        mask = stream->raw_mask << (uframe & 7);
 
+       /* for OUT, don't wrap SSPLIT into H-microframe 7 */
+       if (((stream->raw_mask & 0xff) << (uframe & 7)) >= (1 << 7))
+               return 0;
+
        /* for IN, don't wrap CSPLIT into the next frame */
        if (mask & ~0xffff)
                return 0;