2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------

From: Bjørn Mork <bjorn@mork.no>

commit c428b70c1e115c5649707a602742e34130d19428 upstream.

wdm_in_callback() will also touch this field, so we cannot change it without locking

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/class/cdc-wdm.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -458,7 +458,9 @@ retry:
 	for (i = 0; i < desc->length - cntr; i++)
 		desc->ubuf[i] = desc->ubuf[i + cntr];
 
+	spin_lock_irq(&desc->iuspin);
 	desc->length -= cntr;
+	spin_unlock_irq(&desc->iuspin);
 	/* in case we had outstanding data */
 	if (!desc->length)
 		clear_bit(WDM_READ, &desc->flags);