From: Guo-Fu Tseng <cooldavid@cooldavid.org>
Date: Mon, 18 Oct 2010 11:56:20 +0000 (+0800)
Subject: jme: Prevent possible read re-order error
X-Git-Tag: 1.0.7~4
X-Git-Url: http://bbs.cooldavid.org/git/?p=jme.git;a=commitdiff_plain;h=1a7a122d423969fa759576f60ca2feb3d69be066;ds=sidebyside

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>
---

diff --git a/jme.c b/jme.c
index 0ea0da3..095f899 100644
--- a/jme.c
+++ b/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 ||