[Xen-devel] [PATCH][linux 2.6.18] pvusb: mark request as consumed after finished using it

[Juergen Gross <jgross@xxxxxxxx>]

A request from the pvusb frontend should be marked as consumed by the
backend only after the backend isn't accessing the request data in the
communication ring any more.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

diff -r 2b001f768b76 drivers/xen/usbback/usbback.c
--- a/drivers/xen/usbback/usbback.c     Tue Jul 08 11:53:53 2014 +0200
+++ b/drivers/xen/usbback/usbback.c     Fri Sep 26 11:01:57 2014 +0200
@@ -1003,10 +1003,10 @@ static int usbbk_start_submit_urb(usbif_
                }
 
                req = RING_GET_REQUEST(urb_ring, rc);
-               urb_ring->req_cons = ++rc;
 
                dispatch_request_to_pending_reqs(usbif, req,
                                                        pending_req);
+               urb_ring->req_cons = ++rc;
 
                cond_resched();
        }

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