rt2x00: Don't call ieee80211_get_tx_rate for MCS rates

ieee80211_get_tx_rate is not valid for HT rates. Hence, restructure the
TX desciptor creation to be aware of MCS rates. The generic TX desciptor
creation now cares about the rate_mode (CCK, OFDM, MCS, GF).

As a result, ieee80211_get_tx_rate gets only called for legacy rates.
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2x00ht.c

@@ -77,14 +77,6 @@ void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
 	    !(tx_info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE))
 		__set_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags);
 
-	/*
-	 * Determine HT Mix/Greenfield rate mode
-	 */
-	if (txrate->flags & IEEE80211_TX_RC_MCS)
-		txdesc->rate_mode = RATE_MODE_HT_MIX;
-	if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
-		txdesc->rate_mode = RATE_MODE_HT_GREENFIELD;
-
 	/*
 	 * Set 40Mhz mode if necessary (for legacy rates this will
 	 * duplicate the frame to both channels).

drivers/net/wireless/rt2x00/rt2x00queue.c

@@ -321,9 +321,9 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
-	struct ieee80211_rate *rate =
-	    ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
-	const struct rt2x00_rate *hwrate;
+	struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
+	struct ieee80211_rate *rate;
+	const struct rt2x00_rate *hwrate = NULL;
 
 	memset(txdesc, 0, sizeof(*txdesc));
 
@@ -390,10 +390,18 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
 	/*
 	 * Determine rate modulation.
 	 */
-	hwrate = rt2x00_get_rate(rate->hw_value);
-	txdesc->rate_mode = RATE_MODE_CCK;
-	if (hwrate->flags & DEV_RATE_OFDM)
-		txdesc->rate_mode = RATE_MODE_OFDM;
+	if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
+		txdesc->rate_mode = RATE_MODE_HT_GREENFIELD;
+	else if (txrate->flags & IEEE80211_TX_RC_MCS)
+		txdesc->rate_mode = RATE_MODE_HT_MIX;
+	else {
+		rate = ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
+		hwrate = rt2x00_get_rate(rate->hw_value);
+		if (hwrate->flags & DEV_RATE_OFDM)
+			txdesc->rate_mode = RATE_MODE_OFDM;
+		else
+			txdesc->rate_mode = RATE_MODE_CCK;
+	}
 
 	/*
 	 * Apply TX descriptor handling by components