NTB: correct memory barrier

mmiowb is not sufficient to flush the data and is causing data
corruption.  Change to wmb and the data corruption is no more.

Signed-off-by: Jon Mason <jon.mason@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 1d17857a2d978c9c5e2ac683654c182f6256d9b9..e9666bd7ef4101bc6954ac85534e02334e96ef55 100644 (file)
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -1009,7 +1009,7 @@ static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
        hdr->ver = qp->tx_pkts;
 
        /* Ensure that the data is fully copied out before setting the flag */
        hdr->ver = qp->tx_pkts;
 
        /* Ensure that the data is fully copied out before setting the flag */

-       mmiowb();
+       wmb();

        hdr->flags = entry->flags | DESC_DONE_FLAG;
 
        ntb_ring_sdb(qp->ndev, qp->qp_num);
        hdr->flags = entry->flags | DESC_DONE_FLAG;
 
        ntb_ring_sdb(qp->ndev, qp->qp_num);