Re: [PATCH v2 01/15] net: dsa: Don't set skb->protocol on outgoing tagged packets
From: Florian Fainelli <f.fainelli@gmail.com>
Date: 2014-10-28 19:19:49
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On 10/26/2014 09:52 AM, Guenter Roeck wrote:
Setting skb->protocol to a private protocol type may result in warning messages such as e1000e 0000:00:19.0 em1: checksum_partial proto=dada! This happens if the L3 protocol is IP or IPv6 and skb->ip_summed is set to CHECKSUM_PARTIAL. Looking through the code, it appears that changing skb->protocol for transmitted packets is not necessary and may actually be harmful. Drop it.
You could emphasize that overriding skb->protocol prevents purposely unmodified (from a DSA perspective) network drivers from properly setting up their transmit checksum offload pointers since they inspect skb->protocol to setup the IPv4 header or IPv6 header pointers.
quoted hunk ↗ jump to hunk
Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- v2: - No change net/dsa/tag_dsa.c | 2 -- net/dsa/tag_edsa.c | 2 -- net/dsa/tag_trailer.c | 2 -- 3 files changed, 6 deletions(-)diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c index ce90c8b..2dab270 100644 --- a/net/dsa/tag_dsa.c +++ b/net/dsa/tag_dsa.c@@ -63,8 +63,6 @@ static netdev_tx_t dsa_xmit(struct sk_buff *skb, struct net_device *dev) dsa_header[3] = 0x00; } - skb->protocol = htons(ETH_P_DSA); - skb->dev = p->parent->dst->master_netdev; dev_queue_xmit(skb);diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c index 94fcce7..9aeda59 100644 --- a/net/dsa/tag_edsa.c +++ b/net/dsa/tag_edsa.c@@ -76,8 +76,6 @@ static netdev_tx_t edsa_xmit(struct sk_buff *skb, struct net_device *dev) edsa_header[7] = 0x00; } - skb->protocol = htons(ETH_P_EDSA); - skb->dev = p->parent->dst->master_netdev; dev_queue_xmit(skb);diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c index 115fdca..e268f9d 100644 --- a/net/dsa/tag_trailer.c +++ b/net/dsa/tag_trailer.c@@ -57,8 +57,6 @@ static netdev_tx_t trailer_xmit(struct sk_buff *skb, struct net_device *dev) trailer[2] = 0x10; trailer[3] = 0x00; - nskb->protocol = htons(ETH_P_TRAILER); - nskb->dev = p->parent->dst->master_netdev; dev_queue_xmit(nskb);