From bf08c34086d159edde5c54902dfa2caa4d9fbd8c Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 3 Jan 2018 22:13:00 -0800 Subject: [PATCH 1/3] 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) From 398aff64d5eb441e2191a6b61db04a6e0828b018 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 3 Jan 2018 22:13:01 -0800 Subject: [PATCH 2/3] net: systemport: Remove short packet padding Short packet padding added to the driver is only necessary when using Broadcom tags, but since this is now taken care of net/dsa/tag_brcm.c, we are guaranteed being given correctly padded packets. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 087f01b4dc3a..f15a8fc6dfc9 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -1216,18 +1216,6 @@ static netdev_tx_t bcm_sysport_xmit(struct sk_buff *skb, goto out; } - /* 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. - */ - if (skb_put_padto(skb, ETH_ZLEN + ENET_BRCM_TAG_LEN)) { - ret = NETDEV_TX_OK; - goto out; - } - /* Insert TSB and checksum infos */ if (priv->tsb_en) { skb = bcm_sysport_insert_tsb(skb, dev); From c979da77b3d73b6f2d57ec8b584f3797c2eff7ab Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 3 Jan 2018 22:13:02 -0800 Subject: [PATCH 3/3] net: bgmac: Remove short packet padding for DSA DSA now correctly pads short packets within net/dsa/tag_brcm.c such that this it is no longer necessary to do this within bgmac. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bgmac.c | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c index 1d96cd594ade..8eef9fb6b1fe 100644 --- a/drivers/net/ethernet/broadcom/bgmac.c +++ b/drivers/net/ethernet/broadcom/bgmac.c @@ -128,8 +128,6 @@ bgmac_dma_tx_add_buf(struct bgmac *bgmac, struct bgmac_dma_ring *ring, dma_desc->ctl1 = cpu_to_le32(ctl1); } -#define ENET_BRCM_TAG_LEN 4 - static netdev_tx_t bgmac_dma_tx_add(struct bgmac *bgmac, struct bgmac_dma_ring *ring, struct sk_buff *skb) @@ -142,18 +140,6 @@ static netdev_tx_t bgmac_dma_tx_add(struct bgmac *bgmac, u32 flags; int i; - /* 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. - */ - if (netdev_uses_dsa(net_dev)) { - if (skb_put_padto(skb, ETH_ZLEN + ENET_BRCM_TAG_LEN)) - goto err_stats; - } - if (skb->len > BGMAC_DESC_CTL1_LEN) { netdev_err(bgmac->net_dev, "Too long skb (%d)\n", skb->len); goto err_drop; @@ -240,7 +226,6 @@ err_dma_head: err_drop: dev_kfree_skb(skb); -err_stats: net_dev->stats.tx_dropped++; net_dev->stats.tx_errors++; return NETDEV_TX_OK;