ath9k: fix various aggregation related race conditions

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23097 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/mac80211/patches/521-ath9k_aggr_race_fix.patch

@@ -0,0 +1,52 @@
+--- a/drivers/net/wireless/ath/ath9k/xmit.c
++++ b/drivers/net/wireless/ath/ath9k/xmit.c
+@@ -784,17 +784,23 @@ static void ath_tx_sched_aggr(struct ath
+ 		 status != ATH_AGGR_BAW_CLOSED);
+ }
+ 
+-void ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
+-		       u16 tid, u16 *ssn)
++int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
++		      u16 tid, u16 *ssn)
+ {
+ 	struct ath_atx_tid *txtid;
+ 	struct ath_node *an;
+ 
+ 	an = (struct ath_node *)sta->drv_priv;
+ 	txtid = ATH_AN_2_TID(an, tid);
++
++	if (txtid->state & (AGGR_CLEANUP | AGGR_ADDBA_COMPLETE))
++		return -EAGAIN;
++
+ 	txtid->state |= AGGR_ADDBA_PROGRESS;
+ 	txtid->paused = true;
+ 	*ssn = txtid->seq_start;
++
++	return 0;
+ }
+ 
+ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
+--- a/drivers/net/wireless/ath/ath9k/ath9k.h
++++ b/drivers/net/wireless/ath/ath9k/ath9k.h
+@@ -346,8 +346,8 @@ void ath_tx_tasklet(struct ath_softc *sc
+ void ath_tx_edma_tasklet(struct ath_softc *sc);
+ void ath_tx_cabq(struct ieee80211_hw *hw, struct sk_buff *skb);
+ bool ath_tx_aggr_check(struct ath_softc *sc, struct ath_node *an, u8 tidno);
+-void ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
+-		       u16 tid, u16 *ssn);
++int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
++		      u16 tid, u16 *ssn);
+ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid);
+ void ath_tx_aggr_resume(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid);
+ void ath9k_enable_ps(struct ath_softc *sc);
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -1968,7 +1968,7 @@ static int ath9k_ampdu_action(struct iee
+ 		break;
+ 	case IEEE80211_AMPDU_TX_START:
+ 		ath9k_ps_wakeup(sc);
+-		ath_tx_aggr_start(sc, sta, tid, ssn);
++		ret = ath_tx_aggr_start(sc, sta, tid, ssn);
+ 		ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
+ 		ath9k_ps_restore(sc);
+ 		break;

package/mac80211/patches/522-ath9k_aggr_flush.patch

@@ -0,0 +1,131 @@
+--- a/drivers/net/wireless/ath/ath9k/xmit.c
++++ b/drivers/net/wireless/ath/ath9k/xmit.c
+@@ -61,6 +61,8 @@ static int ath_tx_num_badfrms(struct ath
+ 			      struct ath_tx_status *ts, int txok);
+ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
+ 			     int nbad, int txok, bool update_rc);
++static void ath_tx_update_baw(struct ath_softc *sc, struct ath_atx_tid *tid,
++			      int seqno);
+ 
+ enum {
+ 	MCS_HT20,
+@@ -144,18 +146,23 @@ static void ath_tx_flush_tid(struct ath_
+ 	struct ath_txq *txq = &sc->tx.txq[tid->ac->qnum];
+ 	struct ath_buf *bf;
+ 	struct list_head bf_head;
+-	INIT_LIST_HEAD(&bf_head);
++	struct ath_tx_status ts;
+ 
+-	WARN_ON(!tid->paused);
++	INIT_LIST_HEAD(&bf_head);
+ 
++	memset(&ts, 0, sizeof(ts));
+ 	spin_lock_bh(&txq->axq_lock);
+-	tid->paused = false;
+ 
+ 	while (!list_empty(&tid->buf_q)) {
+ 		bf = list_first_entry(&tid->buf_q, struct ath_buf, list);
+-		BUG_ON(bf_isretried(bf));
+ 		list_move_tail(&bf->list, &bf_head);
+-		ath_tx_send_ht_normal(sc, txq, tid, &bf_head);
++
++		if (bf_isretried(bf)) {
++			ath_tx_update_baw(sc, tid, bf->bf_seqno);
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 0);
++		} else {
++			ath_tx_send_ht_normal(sc, txq, tid, &bf_head);
++		}
+ 	}
+ 
+ 	spin_unlock_bh(&txq->axq_lock);
+@@ -430,7 +437,7 @@ static void ath_tx_complete_aggr(struct 
+ 			list_move_tail(&bf->list, &bf_head);
+ 		}
+ 
+-		if (!txpending) {
++		if (!txpending || (tid->state & AGGR_CLEANUP)) {
+ 			/*
+ 			 * complete the acked-ones/xretried ones; update
+ 			 * block-ack window
+@@ -451,6 +458,7 @@ static void ath_tx_complete_aggr(struct 
+ 				!txfail, sendbar);
+ 		} else {
+ 			/* retry the un-acked ones */
++
+ 			if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)) {
+ 				if (bf->bf_next == NULL && bf_last->bf_stale) {
+ 					struct ath_buf *tbf;
+@@ -509,15 +517,12 @@ static void ath_tx_complete_aggr(struct 
+ 	}
+ 
+ 	if (tid->state & AGGR_CLEANUP) {
++		ath_tx_flush_tid(sc, tid);
++
+ 		if (tid->baw_head == tid->baw_tail) {
+ 			tid->state &= ~AGGR_ADDBA_COMPLETE;
+ 			tid->state &= ~AGGR_CLEANUP;
+-
+-			/* send buffered frames as singles */
+-			ath_tx_flush_tid(sc, tid);
+ 		}
+-		rcu_read_unlock();
+-		return;
+ 	}
+ 
+ 	rcu_read_unlock();
+@@ -808,12 +813,6 @@ void ath_tx_aggr_stop(struct ath_softc *
+ 	struct ath_node *an = (struct ath_node *)sta->drv_priv;
+ 	struct ath_atx_tid *txtid = ATH_AN_2_TID(an, tid);
+ 	struct ath_txq *txq = &sc->tx.txq[txtid->ac->qnum];
+-	struct ath_tx_status ts;
+-	struct ath_buf *bf;
+-	struct list_head bf_head;
+-
+-	memset(&ts, 0, sizeof(ts));
+-	INIT_LIST_HEAD(&bf_head);
+ 
+ 	if (txtid->state & AGGR_CLEANUP)
+ 		return;
+@@ -823,31 +822,22 @@ void ath_tx_aggr_stop(struct ath_softc *
+ 		return;
+ 	}
+ 
+-	/* drop all software retried frames and mark this TID */
+ 	spin_lock_bh(&txq->axq_lock);
+ 	txtid->paused = true;
+-	while (!list_empty(&txtid->buf_q)) {
+-		bf = list_first_entry(&txtid->buf_q, struct ath_buf, list);
+-		if (!bf_isretried(bf)) {
+-			/*
+-			 * NB: it's based on the assumption that
+-			 * software retried frame will always stay
+-			 * at the head of software queue.
+-			 */
+-			break;
+-		}
+-		list_move_tail(&bf->list, &bf_head);
+-		ath_tx_update_baw(sc, txtid, bf->bf_seqno);
+-		ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 0);
+-	}
+-	spin_unlock_bh(&txq->axq_lock);
+ 
+-	if (txtid->baw_head != txtid->baw_tail) {
++	/*
++	 * If frames are still being transmitted for this TID, they will be
++	 * cleaned up during tx completion. To prevent race conditions, this
++	 * TID can only be reused after all in-progress subframes have been
++	 * completed.
++	 */
++	if (txtid->baw_head != txtid->baw_tail)
+ 		txtid->state |= AGGR_CLEANUP;
+-	} else {
++	else
+ 		txtid->state &= ~AGGR_ADDBA_COMPLETE;
+-		ath_tx_flush_tid(sc, txtid);
+-	}
++	spin_unlock_bh(&txq->axq_lock);
++
++	ath_tx_flush_tid(sc, txtid);
+ }
+ 
+ void ath_tx_aggr_resume(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)