[3.13.y.z extended stable] Patch "tg3: Work around HW/FW limitations with vlan encapsulated frames" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    tg3: Work around HW/FW limitations with vlan encapsulated frames

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.11.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 4377243dd21b4eb44baacb1d7dd7fd8aa4d5c706 Mon Sep 17 00:00:00 2001
From: Vlad Yasevich <vyasevich at gmail.com>
Date: Thu, 18 Sep 2014 10:31:17 -0400
Subject: tg3: Work around HW/FW limitations with vlan encapsulated frames

[ Upstream commit 476c18850c6cbaa3f2bb661ae9710645081563b9 ]

TG3 appears to have an issue performing TSO and checksum offloading
correclty when the frame has been vlan encapsulated (non-accelrated).
In these cases, tcp checksum is not correctly updated.

This patch attempts to work around this issue.  After the patch,
802.1ad vlans start working correctly over tg3 devices.

CC: Prashant Sreedharan <prashant at broadcom.com>
CC: Michael Chan <mchan at broadcom.com>
Signed-off-by: Vladislav Yasevich <vyasevic at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index e71ee9f..072f401 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -7899,8 +7899,6 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)

 	entry = tnapi->tx_prod;
 	base_flags = 0;
-	if (skb->ip_summed == CHECKSUM_PARTIAL)
-		base_flags |= TXD_FLAG_TCPUDP_CSUM;

 	mss = skb_shinfo(skb)->gso_size;
 	if (mss) {
@@ -7916,6 +7914,13 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)

 		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb) - ETH_HLEN;

+		/* HW/FW can not correctly segment packets that have been
+		 * vlan encapsulated.
+		 */
+		if (skb->protocol == htons(ETH_P_8021Q) ||
+		    skb->protocol == htons(ETH_P_8021AD))
+			return tg3_tso_bug(tp, skb);
+
 		if (!skb_is_gso_v6(skb)) {
 			iph->check = 0;
 			iph->tot_len = htons(mss + hdr_len);
@@ -7962,6 +7967,17 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
 				base_flags |= tsflags << 12;
 			}
 		}
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		/* HW/FW can not correctly checksum packets that have been
+		 * vlan encapsulated.
+		 */
+		if (skb->protocol == htons(ETH_P_8021Q) ||
+		    skb->protocol == htons(ETH_P_8021AD)) {
+			if (skb_checksum_help(skb))
+				goto drop;
+		} else  {
+			base_flags |= TXD_FLAG_TCPUDP_CSUM;
+		}
 	}

 	if (tg3_flag(tp, USE_JUMBO_BDFLAG) &&
--
1.9.1