ath9k: fix powersave frame filtering/buffering in AP mode

This patch fixes a long standing issue of pending packets in the queue being
sent (and retransmitted many times) to sleeping stations.
This was made worse by aggregation through driver-internal retransmitting
of A-MDPU subframes.
Previously the hardware tx filter was cleared unconditionally for every
single packet - with this patch it uses the IEEE80211_TX_CTL_CLEAR_PS_FILT
for unaggregated frames.
A sta_notify driver op is added to stop aggregation for stations when they
enter powersave mode. Subframes stay buffered inside the driver, to ensure
that the BlockAck window keeps a sane state.
Since the driver uses software aggregation, the clearing of the tx filter
needs to be handled by the driver instead of mac80211 for aggregated frames.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 89 insertions, 12 deletions

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 5943bdc4c8f..48ff8c22ba1 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -357,6 +357,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 	struct ath_frame_info *fi;
 	int nframes;
 	u8 tidno;
+	bool clear_filter;
 
 	skb = bf->bf_mpdu;
 	hdr = (struct ieee80211_hdr *)skb->data;
@@ -441,22 +442,24 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 			/* transmit completion */
 			acked_cnt++;
 		} else {
-			if (!(tid->state & AGGR_CLEANUP) && retry) {
-				if (fi->retries < ATH_MAX_SW_RETRIES) {
-					ath_tx_set_retry(sc, txq, bf->bf_mpdu);
-					txpending = 1;
-				} else {
-					bf->bf_state.bf_type |= BUF_XRETRY;
-					txfail = 1;
-					sendbar = 1;
-					txfail_cnt++;
-				}
-			} else {
+			if ((tid->state & AGGR_CLEANUP) || !retry) {
 				/*
 				 * cleanup in progress, just fail
 				 * the un-acked sub-frames
 				 */
 				txfail = 1;
+			} else if (fi->retries < ATH_MAX_SW_RETRIES) {
+				if (!(ts->ts_status & ATH9K_TXERR_FILT) ||
+				    !an->sleeping)
+					ath_tx_set_retry(sc, txq, bf->bf_mpdu);
+
+				clear_filter = true;
+				txpending = 1;
+			} else {
+				bf->bf_state.bf_type |= BUF_XRETRY;
+				txfail = 1;
+				sendbar = 1;
+				txfail_cnt++;
 			}
 		}
 
@@ -496,6 +499,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 				!txfail, sendbar);
 		} else {
 			/* retry the un-acked ones */
+			ath9k_hw_set_clrdmask(sc->sc_ah, bf->bf_desc, false);
 			if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)) {
 				if (bf->bf_next == NULL && bf_last->bf_stale) {
 					struct ath_buf *tbf;
@@ -546,7 +550,12 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 
 	/* prepend un-acked frames to the beginning of the pending frame queue */
 	if (!list_empty(&bf_pending)) {
+		if (an->sleeping)
+			ieee80211_sta_set_tim(sta);
+
 		spin_lock_bh(&txq->axq_lock);
+		if (clear_filter)
+			tid->ac->clear_ps_filter = true;
 		list_splice(&bf_pending, &tid->buf_q);
 		ath_tx_queue_tid(txq, tid);
 		spin_unlock_bh(&txq->axq_lock);
@@ -816,6 +825,11 @@ static void ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
 		bf = list_first_entry(&bf_q, struct ath_buf, list);
 		bf->bf_lastbf = list_entry(bf_q.prev, struct ath_buf, list);
 
+		if (tid->ac->clear_ps_filter) {
+			tid->ac->clear_ps_filter = false;
+			ath9k_hw_set_clrdmask(sc->sc_ah, bf->bf_desc, true);
+		}
+
 		/* if only one frame, send as non-aggregate */
 		if (bf == bf->bf_lastbf) {
 			fi = get_frame_info(bf->bf_mpdu);
@@ -896,6 +910,67 @@ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
 	ath_tx_flush_tid(sc, txtid);
 }
 
+bool ath_tx_aggr_sleep(struct ath_softc *sc, struct ath_node *an)
+{
+	struct ath_atx_tid *tid;
+	struct ath_atx_ac *ac;
+	struct ath_txq *txq;
+	bool buffered = false;
+	int tidno;
+
+	for (tidno = 0, tid = &an->tid[tidno];
+	     tidno < WME_NUM_TID; tidno++, tid++) {
+
+		if (!tid->sched)
+			continue;
+
+		ac = tid->ac;
+		txq = ac->txq;
+
+		spin_lock_bh(&txq->axq_lock);
+
+		if (!list_empty(&tid->buf_q))
+			buffered = true;
+
+		tid->sched = false;
+		list_del(&tid->list);
+
+		if (ac->sched) {
+			ac->sched = false;
+			list_del(&ac->list);
+		}
+
+		spin_unlock_bh(&txq->axq_lock);
+	}
+
+	return buffered;
+}
+
+void ath_tx_aggr_wakeup(struct ath_softc *sc, struct ath_node *an)
+{
+	struct ath_atx_tid *tid;
+	struct ath_atx_ac *ac;
+	struct ath_txq *txq;
+	int tidno;
+
+	for (tidno = 0, tid = &an->tid[tidno];
+	     tidno < WME_NUM_TID; tidno++, tid++) {
+
+		ac = tid->ac;
+		txq = ac->txq;
+
+		spin_lock_bh(&txq->axq_lock);
+		ac->clear_ps_filter = true;
+
+		if (!list_empty(&tid->buf_q) && !tid->paused) {
+			ath_tx_queue_tid(txq, tid);
+			ath_txq_schedule(sc, txq);
+		}
+
+		spin_unlock_bh(&txq->axq_lock);
+	}
+}
+
 void ath_tx_aggr_resume(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
 {
 	struct ath_atx_tid *txtid;
@@ -1491,7 +1566,6 @@ static int setup_tx_flags(struct sk_buff *skb)
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
 	int flags = 0;
 
-	flags |= ATH9K_TXDESC_CLRDMASK; /* needed for crypto errors */
 	flags |= ATH9K_TXDESC_INTREQ;
 
 	if (tx_info->flags & IEEE80211_TX_CTL_NO_ACK)
@@ -1754,6 +1828,9 @@ static void ath_tx_start_dma(struct ath_softc *sc, struct ath_buf *bf,
 		if (txctl->paprd)
 			bf->bf_state.bfs_paprd_timestamp = jiffies;
 
+		if (tx_info->flags & IEEE80211_TX_CTL_CLEAR_PS_FILT)
+			ath9k_hw_set_clrdmask(sc->sc_ah, bf->bf_desc, true);
+
 		ath_tx_send_normal(sc, txctl->txq, tid, &bf_head);
 	}