From 849b920e17a2b1e9a3c912ca960dc667d27985e8 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Thu, 30 Apr 2015 14:53:48 -0700 Subject: [PATCH] etherdev: Avoid unnecessary byte swap in check for Ethertype This change takes advantage of the fact that ETH_P_802_3_MIN is aligned to 512 so as a result we can actually ignore the lower 8b when comparing the Ethertype to ETH_P_802_3_MIN. This allows us to avoid a byte swap by simply masking the value and comparing it to the byte swapped value for ETH_P_802_3_MIN. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ethernet/eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c index f3bad41..6006931 100644 --- a/net/ethernet/eth.c +++ b/net/ethernet/eth.c @@ -178,7 +178,7 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) if (unlikely(netdev_uses_dsa(dev))) return htons(ETH_P_XDSA); - if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN)) + if (likely((eth->h_proto & htons(0xFF00)) >= htons(ETH_P_802_3_MIN))) return eth->h_proto; /* -- 2.7.4