mac80211: add support for setting the ad-hoc multicast rate

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 33f7699..76de4f8 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -211,10 +211,20 @@
 	return (info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc);
 }
 
-static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx)
+static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u32 mcast_rate,
+				  struct ieee80211_supported_band *sband)
 {
 	u8 i;
 
+	if (mcast_rate) {
+		for (i = 0; i < sband->n_bitrates; i++) {
+			if (sband->bitrates[i].bitrate == mcast_rate) {
+				*idx = i;
+				return;
+			}
+		}
+	}
+
 	if (basic_rates == 0)
 		return; /* assume basic rates unknown and accept rate */
 	if (*idx < 0)
@@ -222,7 +232,7 @@
 	if (basic_rates & (1 << *idx))
 		return; /* selected rate is a basic rate */
 
-	for (i = *idx + 1; i <= max_rate_idx; i++) {
+	for (i = *idx + 1; i <= sband->n_bitrates; i++) {
 		if (basic_rates & (1 << i)) {
 			*idx = i;
 			return;
@@ -243,10 +253,11 @@
 		info->control.rates[0].count =
 			(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 			1 : txrc->hw->max_rate_tries;
-		if (!sta && txrc->ap)
+		if (!sta && txrc->bss)
 			rc_send_low_broadcast(&info->control.rates[0].idx,
 					      txrc->bss_conf->basic_rates,
-					      txrc->sband->n_bitrates);
+					      txrc->bss_conf->mcast_rate,
+					      txrc->sband);
 		return true;
 	}
 	return false;