mac80211: fix RX sequence number check

According to 802.11-2007, we are doing the wrong thing in the
sequence number checks when receiving frames. This fixes it.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rx.c

@@ -334,13 +334,18 @@ static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 		else
 			rx->flags &= ~IEEE80211_RX_AMSDU;
 	} else {
-		if (unlikely(ieee80211_is_mgmt(hdr->frame_control))) {
-			/* Separate TID for management frames */
-			tid = NUM_RX_DATA_QUEUES - 1;
-		} else {
-			/* no qos control present */
-			tid = 0; /* 802.1d - Best Effort */
-		}
+		/*
+		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
+		 *
+		 *	Sequence numbers for management frames, QoS data
+		 *	frames with a broadcast/multicast address in the
+		 *	Address 1 field, and all non-QoS data frames sent
+		 *	by QoS STAs are assigned using an additional single
+		 *	modulo-4096 counter, [...]
+		 *
+		 * We also use that counter for non-QoS STAs.
+		 */
+		tid = NUM_RX_DATA_QUEUES - 1;
 	}
 
 	rx->queue = tid;