From: Jon Mason <jon.mason@intel.com>
Date: Sat, 19 Jan 2013 09:02:17 +0000 (-0700)
Subject: NTB: correct memory barrier
X-Git-Tag: v3.12-rc1~1403^2~53
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=842c1ddea5f9949cb21e568408d2af9d986eee69;p=kernel%2Fkernel-generic.git

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 1d17857..e9666bd 100644
--- 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 */
-	mmiowb();
+	wmb();
 	hdr->flags = entry->flags | DESC_DONE_FLAG;
 
 	ntb_ring_sdb(qp->ndev, qp->qp_num);