From 8ccd8f21122dcc30a665516d43aa8b4aa8ae51f6 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes@sipsolutions.net>
Date: Wed, 29 Apr 2009 23:35:56 +0200
Subject: [PATCH] mac80211: correct fragmentation threshold check

The fragmentation threshold is defined to be including the
FCS, and the code that sets the TX_FRAGMENTED flag correctly
accounts for those four bytes. The code that verifies this
doesn't though, which could lead to spurious warnings and
frames being dropped although everything is ok. Correct the
code by accounting for the FCS.

(JWL -- The problem is described here:
 http://article.gmane.org/gmane.linux.kernel.wireless.general/32205 )

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 net/mac80211/tx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 3fb04a86444d..63656266d567 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -772,7 +772,7 @@ ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
 
 	/* internal error, why is TX_FRAGMENTED set? */
-	if (WARN_ON(skb->len <= frag_threshold))
+	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
 		return TX_DROP;
 
 	/*
-- 
2.34.1