Commit e1e78db6 authored by Jesse Gross's avatar Jesse Gross Committed by David S. Miller
Browse files

offloading: Make scatter/gather more tolerant of vlans.

When checking if it is necessary to linearize a packet, we currently
use vlan_features if the packet contains either an in-band or out-
of-band vlan tag.  However, in-band tags aren't special in any way
for scatter/gather since they are part of the packet buffer and are
simply more data to DMA.  Therefore, only use vlan_features for out-
of-band tags, which could potentially have some interaction with

Signed-off-by: default avatarJesse Gross <>
CC: Ben Hutchings <>
Reviewed-by: default avatarBen Hutchings <>
Signed-off-by: default avatarDavid S. Miller <>
parent 410989f6
......@@ -1976,15 +1976,20 @@ static inline void skb_orphan_try(struct sk_buff *skb)
static inline int skb_needs_linearize(struct sk_buff *skb,
struct net_device *dev)
int features = dev->features;
if (skb_is_nonlinear(skb)) {
int features = dev->features;
if (skb->protocol == htons(ETH_P_8021Q) || vlan_tx_tag_present(skb))
features &= dev->vlan_features;
if (vlan_tx_tag_present(skb))
features &= dev->vlan_features;
return skb_is_nonlinear(skb) &&
((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
(skb_shinfo(skb)->nr_frags && (!(features & NETIF_F_SG) ||
illegal_highdma(dev, skb))));
return (skb_has_frag_list(skb) &&
!(features & NETIF_F_FRAGLIST)) ||
(skb_shinfo(skb)->nr_frags &&
(!(features & NETIF_F_SG) ||
illegal_highdma(dev, skb)));
return 0;
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
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