diff mbox

[net-next,1/3] tg3: Don't modify ip header fields when doing GSO

Message ID 1399864975-29070-2-git-send-email-mchan@broadcom.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Michael Chan May 12, 2014, 3:22 a.m. UTC 
tg3 uses GSO as workaround if the hardware cannot perform TSO on certain
packets.  We should not modify the ip header fields if we do GSO on the
packet.  It happens to work by accident because GSO recalculates the IP
checksum and IP total length.

Also fix the tg3_start_xmit comment to reflect that this is the only
xmit function for all devices.

Signed-off-by: Prashant Sreedharan <prashant@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
---
 drivers/net/ethernet/broadcom/tg3.c |   12 +++++-------
 1 files changed, 5 insertions(+), 7 deletions(-)
diff mbox

Patch

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index e5d95c5..bdfd08b 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -7871,9 +7871,7 @@  tg3_tso_bug_end:
 	return NETDEV_TX_OK;
 }
 
-/* hard_start_xmit for devices that have the 4G bug and/or 40-bit bug and
- * support TG3_FLAG_HW_TSO_1 or firmware TSO only.
- */
+/* hard_start_xmit for all devices */
 static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct tg3 *tp = netdev_priv(dev);
@@ -7927,14 +7925,14 @@  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;
 
 		if (!skb_is_gso_v6(skb)) {
+			if (unlikely((ETH_HLEN + hdr_len) > 80) &&
+			    tg3_flag(tp, TSO_BUG))
+				return tg3_tso_bug(tp, skb);
+
 			iph->check = 0;
 			iph->tot_len = htons(mss + hdr_len);
 		}
 
-		if (unlikely((ETH_HLEN + hdr_len) > 80) &&
-		    tg3_flag(tp, TSO_BUG))
-			return tg3_tso_bug(tp, skb);
-
 		base_flags |= (TXD_FLAG_CPU_PRE_DMA |
 			       TXD_FLAG_CPU_POST_DMA);