mac80211: add helper for management / no-ack frame rate decision

All current rate control algorithms agree to send management and no-ack
frames at the lowest rate. They also agree to do this when sta
and the private rate control data is NULL. We add a hlper to mac80211
for this and simplify the rate control algorithm code.

Developers wishing to make enhancements to rate control algorithms
are for broadcast/multicast can opt to not use this in their
gate_rate() mac80211 callback.

Cc: Zhu Yi <yi.zhu@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: ipw3945-devel@lists.sourceforge.net
Cc: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Cc: Derek Smithies <derek@indranet.co.nz>
Cc: Chittajit Mitra <Chittajit.Mitra@Atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 31 insertions, 31 deletions

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 4641f00a1e5c..8ac7a984d886 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -198,6 +198,35 @@ static void rate_control_release(struct kref *kref)
 	kfree(ctrl_ref);
 }
 
+static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc)
+{
+	struct sk_buff *skb = txrc->skb;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	__le16 fc;
+
+	fc = hdr->frame_control;
+
+	return ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc));
+}
+
+bool rate_control_send_low(struct ieee80211_sta *sta,
+			   void *priv_sta,
+			   struct ieee80211_tx_rate_control *txrc)
+{
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
+
+	if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) {
+		info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
+		info->control.rates[0].count =
+			(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
+			1 : txrc->hw->max_rate_tries;
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL(rate_control_send_low);
+
 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 			   struct sta_info *sta,
 			   struct ieee80211_tx_rate_control *txrc)
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 5bdce0c951dd..7c5142988bbb 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -70,19 +70,6 @@ rix_to_ndx(struct minstrel_sta_info *mi, int rix)
 	return i;
 }
 
-static inline bool
-use_low_rate(struct sk_buff *skb)
-{
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	__le16 fc;
-
-	fc = hdr->frame_control;
-
-	return ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc));
-}
-
-
 static void
 minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 {
@@ -231,7 +218,6 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
 		  void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 {
 	struct sk_buff *skb = txrc->skb;
-	struct ieee80211_supported_band *sband = txrc->sband;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct minstrel_sta_info *mi = priv_sta;
 	struct minstrel_priv *mp = priv;
@@ -244,14 +230,8 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
 	int mrr_ndx[3];
 	int sample_rate;
 
-	if (!sta || !mi || use_low_rate(skb)) {
-		ar[0].idx = rate_lowest_index(sband, sta);
-		if (info->flags & IEEE80211_TX_CTL_NO_ACK)
-			ar[0].count = 1;
-		else
-			ar[0].count = mp->max_retry;
+	if (rate_control_send_low(sta, priv_sta, txrc))
 		return;
-	}
 
 	mrr = mp->has_mrr && !txrc->rts && !txrc->bss_conf->use_cts_prot;
 
diff --git a/net/mac80211/rc80211_pid_algo.c b/net/mac80211/rc80211_pid_algo.c
index 549607703bd8..8c053be9dc24 100644
--- a/net/mac80211/rc80211_pid_algo.c
+++ b/net/mac80211/rc80211_pid_algo.c
@@ -276,11 +276,9 @@ rate_control_pid_get_rate(void *priv, struct ieee80211_sta *sta,
 {
 	struct sk_buff *skb = txrc->skb;
 	struct ieee80211_supported_band *sband = txrc->sband;
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct rc_pid_sta_info *spinfo = priv_sta;
 	int rateidx;
-	__le16 fc;
 
 	if (txrc->rts)
 		info->control.rates[0].count =
@@ -290,15 +288,8 @@ rate_control_pid_get_rate(void *priv, struct ieee80211_sta *sta,
 			txrc->hw->conf.short_frame_max_tx_count;
 
 	/* Send management frames and NO_ACK data using lowest rate. */
-	fc = hdr->frame_control;
-	if (!sta || !spinfo || !ieee80211_is_data(fc) ||
-	    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;
-
+	if (rate_control_send_low(sta, priv_sta, txrc))
 		return;
-	}
 
 	rateidx = spinfo->txrate_idx;