From bf08c34086d159edde5c54902dfa2caa4d9fbd8c Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 3 Jan 2018 22:13:00 -0800 Subject: [PATCH] net: dsa: Move padding into Broadcom tagger Instead of having the different master network device drivers potentially used by DSA/Broadcom tags, move the padding necessary for the switches to accept short packets where it makes most sense: within tag_brcm.c. This avoids multiplying the number of similar commits to e.g: bgmac, bcmsysport, etc. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/tag_brcm.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c index e6e0b7b6025c..2b06bb91318b 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -70,6 +70,18 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, if (skb_cow_head(skb, BRCM_TAG_LEN) < 0) return NULL; + /* The Ethernet switch we are interfaced with needs packets to be at + * least 64 bytes (including FCS) otherwise they will be discarded when + * they enter the switch port logic. When Broadcom tags are enabled, we + * need to make sure that packets are at least 68 bytes + * (including FCS and tag) because the length verification is done after + * the Broadcom tag is stripped off the ingress packet. + * + * Let dsa_slave_xmit() free the SKB + */ + if (__skb_put_padto(skb, ETH_ZLEN + BRCM_TAG_LEN, false)) + return NULL; + skb_push(skb, BRCM_TAG_LEN); if (offset)