From: Johannes Berg <johannes@sipsolutions.net>
Date: Tue, 13 May 2008 03:51:44 +0000 (-0700)
Subject: mac80211: assign needed_headroom/tailroom for netdevs
X-Git-Tag: v2.6.26-rc3~65^2~11
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f3994eceebf64cf356a82ffb2718ef538eb8d4f4;p=linux-2.6

mac80211: assign needed_headroom/tailroom for netdevs

This assigns the netdev's needed_headroom/tailroom members to take
advantage of pre-allocated space for 802.11 headers.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 80954a5121..06e88a5a03 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -54,6 +54,15 @@ int ieee80211_if_add(struct net_device *dev, const char *name,
 	if (!ndev)
 		return -ENOMEM;
 
+	ndev->needed_headroom = local->tx_headroom +
+				4*6 /* four MAC addresses */
+				+ 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
+				+ 6 /* mesh */
+				+ 8 /* rfc1042/bridge tunnel */
+				- ETH_HLEN /* ethernet hard_header_len */
+				+ IEEE80211_ENCRYPT_HEADROOM;
+	ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
+
 	ret = dev_alloc_name(ndev, ndev->name);
 	if (ret < 0)
 		goto fail;