From: Johannes Berg <johannes.berg@xxxxxxxxx> If drivers want to support S/G (really just gather DMA on TX) then we can now easily support this on the fast-xmit path since it just needs to write to the ethernet header (and already has a check for that being possible.) However, disallow this on the regular TX path (which has to handle fragmentation, software crypto, etc.) by calling skb_linearize(). Also allow the related HIGHDMA since that's not interesting to the code in mac80211 at all anyway. Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> --- net/mac80211/ieee80211_i.h | 3 ++- net/mac80211/tx.c | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 3f837fea05ae..25a456c48043 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -86,7 +86,8 @@ struct ieee80211_local; /* Only these features can be passed through mac80211 */ #define IEEE80211_SUPPORTED_NETDEV_FEATURES \ (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | \ - NETIF_F_HW_CSUM | NETIF_F_RXCSUM) + NETIF_F_HW_CSUM | NETIF_F_RXCSUM | \ + NETIF_F_SG | NETIF_F_HIGHDMA) struct ieee80211_fragment_entry { unsigned long first_frag_time; diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index e76f3e96eb84..53a16257dfc1 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2848,6 +2848,12 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, goto out; } + /* we cannot process non-linear frames on this path */ + if (skb_linearize(skb)) { + kfree_skb(skb); + goto out; + } + /* the frame could be fragmented, software-encrypted, and other things * so we cannot really handle checksum offload with it - fix it up in * software before we handle anything else. -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html