From: Hans-Joachim Picht <hpicht@redhat.com>
Date: Fri, 25 Apr 2008 15:07:12 +0200
Subject: [s390] qeth: eddp skb buff problem running EDDP guestlan
Message-id: 20080425130712.GB22728@redhat.com
O-Subject: [RHEL5 U3 PATCH 2/5] s390 - qeth: eddp skb buff problem running EDDP guestlan
Bugzilla: 444014
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>
RH-Acked-by: John W. Linville <linville@redhat.com>

Description
============

Packet Length in qdio header is broken when using
EDDP on Layer2 devices. This leads to skb_under_panic on receiver
system when running on z/VM GuestLAN devices.

Bugzilla
=========

BZ 444014
https://bugzilla.redhat.com/show_bug.cgi?id=444014

Upstream status of the patch:
=============================

Patch is contained in linux-2.6 as git commit
cd3e76ebcb41c48ef6e706006b793d45030bae75

Test status:
============

The patch has been tested and fixes the problem.
The fix has been verified by the IBM test department.

Please ACK.

With best regards,

Hans

diff --git a/drivers/s390/net/qeth_eddp.c b/drivers/s390/net/qeth_eddp.c
index a363721..60147fe 100644
--- a/drivers/s390/net/qeth_eddp.c
+++ b/drivers/s390/net/qeth_eddp.c
@@ -422,9 +422,8 @@ __qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 			       (int)(eddp->skb->len - eddp->skb_offset));
 		/* prepare qdio hdr */
 		if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
-			eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
-						     eddp->nhl + eddp->thl -
-						     sizeof(struct qeth_hdr);
+			eddp->qh.hdr.l2.pkt_length =
+				 data_len + ETH_HLEN + eddp->nhl + eddp->thl;
 #ifdef CONFIG_QETH_VLAN
 			if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
 				eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;