From: Guo-Fu Tseng <cooldavid@cooldavid.org>
Date: Mon, 18 Oct 2010 14:10:42 +0000 (+0000)
Subject: jme: Prevent possible read re-order error
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ea192aa89c3b26d56113e70c72238f6951d4097f;p=mv-sheeva.git

jme: Prevent possible read re-order error

Adding read memory barrier in between flag reading and data reading of
receive descriptors. This prevents the data being read before hardware
complete writing informations.

Reported-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/jme.c b/drivers/net/jme.c
index 0ea0da32d7d..095f8998714 100644
--- a/drivers/net/jme.c
+++ b/drivers/net/jme.c
@@ -989,6 +989,7 @@ jme_process_receive(struct jme_adapter *jme, int limit)
 			goto out;
 		--limit;
 
+		rmb();
 		desccnt = rxdesc->descwb.desccnt & RXWBDCNT_DCNT;
 
 		if (unlikely(desccnt > 1 ||