mac80211: Fix handling of retry count of NO_ACK frames in PID

Make PID check for IEEE80211_TX_CTL_NO_ACK instead of
is_multicast_ether_addr when determining whether to use the lowest
rate, and set the retry count to 0 (total try count = 1) if
IEEE80211_TX_CTL_NO_ACK is set.
Signed-off-by: NGábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/rc80211_pid_algo.c

@@ -289,13 +289,15 @@ rate_control_pid_get_rate(void *priv, struct ieee80211_sta *sta,
 		info->control.rates[0].count =
 			txrc->hw->conf.short_frame_max_tx_count;
 
-	/* Send management frames and broadcast/multicast data using lowest
-	 * rate. */
+	/* Send management frames and NO_ACK data using lowest rate. */
 	fc = le16_to_cpu(hdr->frame_control);
 	if (!sta || !spinfo ||
 	    (fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
-	    is_multicast_ether_addr(hdr->addr1)) {
+	    info->flags & IEEE80211_TX_CTL_NO_ACK) {
 		info->control.rates[0].idx = rate_lowest_index(sband, sta);
+		if (info->flags & IEEE80211_TX_CTL_NO_ACK)
+			info->control.rates[0].count = 1;
+
 		return;
 	}