ath9k: Assign seq# when mac80211 requests this

Use TX control flag IEEE80211_TX_CTL_ASSIGN_SEQ as a request to update
the seq# for the frames. This will likely require some further cleanup
to get seq# correctly for Beacons vs. other frames and also potentially
for multiple BSSes. Anyway, this is better than ending up sending out
most frames with seq# 0.

(This is a backport of patch w/ same title already in net-next-2.6.
It is verified to fix http://bugzilla.kernel.org/show_bug.cgi?id=11394
and it should be acceptable for -rc due to the driver being new
in 2.6.27.)

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index c5107f2..99badf1 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -369,6 +369,20 @@
 {
 	struct ath_softc *sc = hw->priv;
 	int hdrlen, padsize;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+
+	/*
+	 * As a temporary workaround, assign seq# here; this will likely need
+	 * to be cleaned up to work better with Beacon transmission and virtual
+	 * BSSes.
+	 */
+	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
+		struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+		if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
+			sc->seq_no += 0x10;
+		hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
+		hdr->seq_ctrl |= cpu_to_le16(sc->seq_no);
+	}
 
 	/* Add the padding after the header if this is not already done */
 	hdrlen = ieee80211_get_hdrlen_from_skb(skb);