1 files changed, 56 insertions, 108 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 34edf7f22b0e..081dcaf6577b 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -33,10 +33,6 @@
 #include "wme.h"
 #include "rate.h"
 
-#define IEEE80211_TX_OK		0
-#define IEEE80211_TX_AGAIN	1
-#define IEEE80211_TX_PENDING	2
-
 /* misc utils */
 
 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
@@ -1285,16 +1281,17 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
 	return TX_CONTINUE;
 }
 
-static int __ieee80211_tx(struct ieee80211_local *local,
-			  struct sk_buff **skbp,
-			  struct sta_info *sta,
-			  bool txpending)
+/*
+ * Returns false if the frame couldn't be transmitted but was queued instead.
+ */
+static bool __ieee80211_tx(struct ieee80211_local *local, struct sk_buff **skbp,
+			   struct sta_info *sta, bool txpending)
 {
 	struct sk_buff *skb = *skbp, *next;
 	struct ieee80211_tx_info *info;
 	struct ieee80211_sub_if_data *sdata;
 	unsigned long flags;
-	int ret, len;
+	int len;
 	bool fragm = false;
 
 	while (skb) {
@@ -1302,13 +1299,37 @@ static int __ieee80211_tx(struct ieee80211_local *local,
 		__le16 fc;
 
 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
-		ret = IEEE80211_TX_OK;
 		if (local->queue_stop_reasons[q] ||
-		    (!txpending && !skb_queue_empty(&local->pending[q])))
-			ret = IEEE80211_TX_PENDING;
+		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
+			/*
+			 * Since queue is stopped, queue up frames for later
+			 * transmission from the tx-pending tasklet when the
+			 * queue is woken again.
+			 */
+
+			do {
+				next = skb->next;
+				skb->next = NULL;
+				/*
+				 * NB: If txpending is true, next must already
+				 * be NULL since we must've gone through this
+				 * loop before already; therefore we can just
+				 * queue the frame to the head without worrying
+				 * about reordering of fragments.
+				 */
+				if (unlikely(txpending))
+					__skb_queue_head(&local->pending[q],
+							 skb);
+				else
+					__skb_queue_tail(&local->pending[q],
+							 skb);
+			} while ((skb = next));
+
+			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
+					       flags);
+			return false;
+		}
 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
-		if (ret != IEEE80211_TX_OK)
-			return ret;
 
 		info = IEEE80211_SKB_CB(skb);
 
@@ -1343,15 +1364,7 @@ static int __ieee80211_tx(struct ieee80211_local *local,
 			info->control.sta = NULL;
 
 		fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
-		ret = drv_tx(local, skb);
-		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
-			dev_kfree_skb(skb);
-			ret = NETDEV_TX_OK;
-		}
-		if (ret != NETDEV_TX_OK) {
-			info->control.vif = &sdata->vif;
-			return IEEE80211_TX_AGAIN;
-		}
+		drv_tx(local, skb);
 
 		ieee80211_tpt_led_trig_tx(local, fc, len);
 		*skbp = skb = next;
@@ -1359,7 +1372,7 @@ static int __ieee80211_tx(struct ieee80211_local *local,
 		fragm = true;
 	}
 
-	return IEEE80211_TX_OK;
+	return true;
 }
 
 /*
@@ -1419,23 +1432,24 @@ static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
 	return 0;
 }
 
-static void ieee80211_tx(struct ieee80211_sub_if_data *sdata,
+/*
+ * Returns false if the frame couldn't be transmitted but was queued instead.
+ */
+static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
 			 struct sk_buff *skb, bool txpending)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_data tx;
 	ieee80211_tx_result res_prepare;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	struct sk_buff *next;
-	unsigned long flags;
-	int ret, retries;
 	u16 queue;
+	bool result = true;
 
 	queue = skb_get_queue_mapping(skb);
 
 	if (unlikely(skb->len < 10)) {
 		dev_kfree_skb(skb);
-		return;
+		return true;
 	}
 
 	rcu_read_lock();
@@ -1445,85 +1459,19 @@ static void ieee80211_tx(struct ieee80211_sub_if_data *sdata,
 
 	if (unlikely(res_prepare == TX_DROP)) {
 		dev_kfree_skb(skb);
-		rcu_read_unlock();
-		return;
+		goto out;
 	} else if (unlikely(res_prepare == TX_QUEUED)) {
-		rcu_read_unlock();
-		return;
+		goto out;
 	}
 
 	tx.channel = local->hw.conf.channel;
 	info->band = tx.channel->band;
 
-	if (invoke_tx_handlers(&tx))
-		goto out;
-
-	retries = 0;
- retry:
-	ret = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
-	switch (ret) {
-	case IEEE80211_TX_OK:
-		break;
-	case IEEE80211_TX_AGAIN:
-		/*
-		 * Since there are no fragmented frames on A-MPDU
-		 * queues, there's no reason for a driver to reject
-		 * a frame there, warn and drop it.
-		 */
-		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
-			goto drop;
-		/* fall through */
-	case IEEE80211_TX_PENDING:
-		skb = tx.skb;
-
-		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
-
-		if (local->queue_stop_reasons[queue] ||
-		    !skb_queue_empty(&local->pending[queue])) {
-			/*
-			 * if queue is stopped, queue up frames for later
-			 * transmission from the tasklet
-			 */
-			do {
-				next = skb->next;
-				skb->next = NULL;
-				if (unlikely(txpending))
-					__skb_queue_head(&local->pending[queue],
-							 skb);
-				else
-					__skb_queue_tail(&local->pending[queue],
-							 skb);
-			} while ((skb = next));
-
-			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
-					       flags);
-		} else {
-			/*
-			 * otherwise retry, but this is a race condition or
-			 * a driver bug (which we warn about if it persists)
-			 */
-			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
-					       flags);
-
-			retries++;
-			if (WARN(retries > 10, "tx refused but queue active\n"))
-				goto drop;
-			goto retry;
-		}
-	}
+	if (!invoke_tx_handlers(&tx))
+		result = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
  out:
 	rcu_read_unlock();
-	return;
-
- drop:
-	rcu_read_unlock();
-
-	skb = tx.skb;
-	while (skb) {
-		next = skb->next;
-		dev_kfree_skb(skb);
-		skb = next;
-	}
+	return result;
 }
 
 /* device xmit handlers */
@@ -2070,6 +2018,11 @@ void ieee80211_clear_tx_pending(struct ieee80211_local *local)
 		skb_queue_purge(&local->pending[i]);
 }
 
+/*
+ * Returns false if the frame couldn't be transmitted but was queued instead,
+ * which in this case means re-queued -- take as an indication to stop sending
+ * more pending frames.
+ */
 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
 				     struct sk_buff *skb)
 {
@@ -2077,20 +2030,17 @@ static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
 	struct ieee80211_sub_if_data *sdata;
 	struct sta_info *sta;
 	struct ieee80211_hdr *hdr;
-	int ret;
-	bool result = true;
+	bool result;
 
 	sdata = vif_to_sdata(info->control.vif);
 
 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
-		ieee80211_tx(sdata, skb, true);
+		result = ieee80211_tx(sdata, skb, true);
 	} else {
 		hdr = (struct ieee80211_hdr *)skb->data;
 		sta = sta_info_get(sdata, hdr->addr1);
 
-		ret = __ieee80211_tx(local, &skb, sta, true);
-		if (ret != IEEE80211_TX_OK)
-			result = false;
+		result = __ieee80211_tx(local, &skb, sta, true);
 	}
 
 	return result;
@@ -2132,8 +2082,6 @@ void ieee80211_tx_pending(unsigned long data)
 						flags);
 
 			txok = ieee80211_tx_pending_skb(local, skb);
-			if (!txok)
-				__skb_queue_head(&local->pending[i], skb);
 			spin_lock_irqsave(&local->queue_stop_reason_lock,
 					  flags);
 			if (!txok)