From b333b7e6ec210412be49d1dc67b62d4e565a0cd6 Mon Sep 17 00:00:00 2001 From: Alan Ott Date: Thu, 29 Nov 2012 15:55:44 +0000 Subject: [PATCH] 6lowpan: consider checksum bytes in fragmentation threshold Change the threshold for framentation of a lowpan packet from using the MTU size to now use the MTU size minus the checksum length, which is added by the hardware. For IEEE 802.15.4, this effectively changes it from 127 bytes to 125 bytes. Signed-off-by: Alan Ott Signed-off-by: David S. Miller --- net/ieee802154/6lowpan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c index 6d42c17af96b..f651da60f161 100644 --- a/net/ieee802154/6lowpan.c +++ b/net/ieee802154/6lowpan.c @@ -1047,7 +1047,8 @@ static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev) goto error; } - if (skb->len <= IEEE802154_MTU) { + /* Send directly if less than the MTU minus the 2 checksum bytes. */ + if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) { err = dev_queue_xmit(skb); goto out; } -- 2.20.1