openwrt/package/mac80211/patches/563-ath9k_simplify_tx_locking.patch

--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -169,13 +169,11 @@ static void ath_tx_flush_tid(struct ath_
 	INIT_LIST_HEAD(&bf_head);
 
 	memset(&ts, 0, sizeof(ts));
-	spin_lock_bh(&txq->axq_lock);
 
 	while ((skb = __skb_dequeue(&tid->buf_q))) {
 		fi = get_frame_info(skb);
 		bf = fi->bf;
 
-		spin_unlock_bh(&txq->axq_lock);
 		if (bf && fi->retries) {
 			list_add_tail(&bf->list, &bf_head);
 			ath_tx_update_baw(sc, tid, bf->bf_state.seqno);
@@ -184,7 +182,6 @@ static void ath_tx_flush_tid(struct ath_
 		} else {
 			ath_tx_send_normal(sc, txq, NULL, skb);
 		}
-		spin_lock_bh(&txq->axq_lock);
 	}
 
 	if (tid->baw_head == tid->baw_tail) {
@@ -192,8 +189,6 @@ static void ath_tx_flush_tid(struct ath_
 		tid->state &= ~AGGR_CLEANUP;
 	}
 
-	spin_unlock_bh(&txq->axq_lock);
-
 	if (sendbar)
 		ath_send_bar(tid, tid->seq_start);
 }
@@ -254,9 +249,7 @@ static void ath_tid_drain(struct ath_sof
 		bf = fi->bf;
 
 		if (!bf) {
-			spin_unlock(&txq->axq_lock);
 			ath_tx_complete(sc, skb, ATH_TX_ERROR, txq);
-			spin_lock(&txq->axq_lock);
 			continue;
 		}
 
@@ -265,9 +258,7 @@ static void ath_tid_drain(struct ath_sof
 		if (fi->retries)
 			ath_tx_update_baw(sc, tid, bf->bf_state.seqno);
 
-		spin_unlock(&txq->axq_lock);
 		ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
-		spin_lock(&txq->axq_lock);
 	}
 
 	tid->seq_next = tid->seq_start;
@@ -525,9 +516,7 @@ static void ath_tx_complete_aggr(struct 
 			 * complete the acked-ones/xretried ones; update
 			 * block-ack window
 			 */
-			spin_lock_bh(&txq->axq_lock);
 			ath_tx_update_baw(sc, tid, seqno);
-			spin_unlock_bh(&txq->axq_lock);
 
 			if (rc_update && (acked_cnt == 1 || txfail_cnt == 1)) {
 				memcpy(tx_info->control.rates, rates, sizeof(rates));
@@ -550,9 +539,7 @@ static void ath_tx_complete_aggr(struct 
 				 * run out of tx buf.
 				 */
 				if (!tbf) {
-					spin_lock_bh(&txq->axq_lock);
 					ath_tx_update_baw(sc, tid, seqno);
-					spin_unlock_bh(&txq->axq_lock);
 
 					ath_tx_complete_buf(sc, bf, txq,
 							    &bf_head, ts, 0);
@@ -582,7 +569,6 @@ static void ath_tx_complete_aggr(struct 
 		if (an->sleeping)
 			ieee80211_sta_set_buffered(sta, tid->tidno, true);
 
-		spin_lock_bh(&txq->axq_lock);
 		skb_queue_splice(&bf_pending, &tid->buf_q);
 		if (!an->sleeping) {
 			ath_tx_queue_tid(txq, tid);
@@ -590,7 +576,6 @@ static void ath_tx_complete_aggr(struct 
 			if (ts->ts_status & ATH9K_TXERR_FILT)
 				tid->ac->clear_ps_filter = true;
 		}
-		spin_unlock_bh(&txq->axq_lock);
 	}
 
 	if (tid->state & AGGR_CLEANUP)
@@ -1190,9 +1175,9 @@ void ath_tx_aggr_stop(struct ath_softc *
 		txtid->state |= AGGR_CLEANUP;
 	else
 		txtid->state &= ~AGGR_ADDBA_COMPLETE;
-	spin_unlock_bh(&txq->axq_lock);
 
 	ath_tx_flush_tid(sc, txtid);
+	spin_unlock_bh(&txq->axq_lock);
 }
 
 void ath_tx_aggr_sleep(struct ieee80211_sta *sta, struct ath_softc *sc,
@@ -1434,8 +1419,6 @@ static bool bf_is_ampdu_not_probing(stru
 
 static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
 			       struct list_head *list, bool retry_tx)
-	__releases(txq->axq_lock)
-	__acquires(txq->axq_lock)
 {
 	struct ath_buf *bf, *lastbf;
 	struct list_head bf_head;
@@ -1462,13 +1445,11 @@ static void ath_drain_txq_list(struct at
 		if (bf_is_ampdu_not_probing(bf))
 			txq->axq_ampdu_depth--;
 
-		spin_unlock_bh(&txq->axq_lock);
 		if (bf_isampdu(bf))
 			ath_tx_complete_aggr(sc, txq, bf, &bf_head, &ts, 0,
 					     retry_tx);
 		else
 			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
-		spin_lock_bh(&txq->axq_lock);
 	}
 }
 
@@ -1847,8 +1828,6 @@ static void ath_tx_start_dma(struct ath_
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
 	struct ath_buf *bf;
 
-	spin_lock_bh(&txctl->txq->axq_lock);
-
 	if ((tx_info->flags & IEEE80211_TX_CTL_AMPDU) && tid) {
 		/*
 		 * Try aggregation if it's a unicast data frame
@@ -1858,7 +1837,7 @@ static void ath_tx_start_dma(struct ath_
 	} else {
 		bf = ath_tx_setup_buffer(sc, txctl->txq, tid, skb);
 		if (!bf)
-			goto out;
+			return;
 
 		bf->bf_state.bfs_paprd = txctl->paprd;
 
@@ -1867,9 +1846,6 @@ static void ath_tx_start_dma(struct ath_
 
 		ath_tx_send_normal(sc, txctl->txq, tid, skb);
 	}
-
-out:
-	spin_unlock_bh(&txctl->txq->axq_lock);
 }
 
 /* Upon failure caller should free skb */
@@ -1949,15 +1925,19 @@ int ath_tx_start(struct ieee80211_hw *hw
 	 */
 
 	q = skb_get_queue_mapping(skb);
+
 	spin_lock_bh(&txq->axq_lock);
+
 	if (txq == sc->tx.txq_map[q] &&
 	    ++txq->pending_frames > ATH_MAX_QDEPTH && !txq->stopped) {
 		ieee80211_stop_queue(sc->hw, q);
 		txq->stopped = 1;
 	}
-	spin_unlock_bh(&txq->axq_lock);
 
 	ath_tx_start_dma(sc, skb, txctl, tid);
+
+	spin_unlock_bh(&txq->axq_lock);
+
 	return 0;
 }
 
@@ -2003,7 +1983,6 @@ static void ath_tx_complete(struct ath_s
 
 	q = skb_get_queue_mapping(skb);
 	if (txq == sc->tx.txq_map[q]) {
-		spin_lock_bh(&txq->axq_lock);
 		if (WARN_ON(--txq->pending_frames < 0))
 			txq->pending_frames = 0;
 
@@ -2011,7 +1990,6 @@ static void ath_tx_complete(struct ath_s
 			ieee80211_wake_queue(sc->hw, q);
 			txq->stopped = 0;
 		}
-		spin_unlock_bh(&txq->axq_lock);
 	}
 
 	ieee80211_tx_status(hw, skb);
@@ -2117,8 +2095,6 @@ static void ath_tx_rc_status(struct ath_
 static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
 				  struct ath_tx_status *ts, struct ath_buf *bf,
 				  struct list_head *bf_head)
-	__releases(txq->axq_lock)
-	__acquires(txq->axq_lock)
 {
 	int txok;
 
@@ -2128,16 +2104,12 @@ static void ath_tx_process_buffer(struct
 	if (bf_is_ampdu_not_probing(bf))
 		txq->axq_ampdu_depth--;
 
-	spin_unlock_bh(&txq->axq_lock);
-
 	if (!bf_isampdu(bf)) {
 		ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok);
 		ath_tx_complete_buf(sc, bf, txq, bf_head, ts, txok);
 	} else
 		ath_tx_complete_aggr(sc, txq, bf, bf_head, ts, txok, true);
 
-	spin_lock_bh(&txq->axq_lock);
-
 	if (sc->sc_flags & SC_OP_TXAGGR)
 		ath_txq_schedule(sc, txq);
 }