ath9k: unify edma and non-edma tx code, improve tx fifo handling

EDMA based chips (AR9380+) have 8 Tx FIFO slots, which are used to fix the
tx queue start/stop race conditions which have to be worked around for
earlier chips by keeping the last descriptor in the queue. The current code
stores all frames that do not fit onto the 8 FIFO slots in a separate
list. Whenever a FIFO slot is freed up, the next frame (or A-MPDU) from the
pending queue gets moved to that slot.

This process is not only inefficient, but also unnecessary. The code can
be improved visibly by keeping the pending queue fully linked, and moving
the contents of the entire queue to a FIFO slot as it becomes available.

This patch makes the necessary changes for that and also merges some code
that was duplicated for EDMA vs non-EDMA. It changes txq->axq_link to point
to the last descriptor instead of the link pointer, so that
ath9k_hw_set_desc_link can be used, which works on all chips.

With this patch, a small performance increase for non-aggregated traffic
was observed on AR9380 based embedded hardware.

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

1 files changed, 137 insertions, 201 deletions

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 3779b8977d47..ec012b4317af 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -53,7 +53,7 @@ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
 				struct ath_txq *txq, struct list_head *bf_q,
 				struct ath_tx_status *ts, int txok, int sendbar);
 static void ath_tx_txqaddbuf(struct ath_softc *sc, struct ath_txq *txq,
-			     struct list_head *head);
+			     struct list_head *head, bool internal);
 static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len);
 static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
 			     struct ath_tx_status *ts, int nframes, int nbad,
@@ -377,8 +377,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 			bf_next = bf->bf_next;
 
 			bf->bf_state.bf_type |= BUF_XRETRY;
-			if ((sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) ||
-			    !bf->bf_stale || bf_next != NULL)
+			if (!bf->bf_stale || bf_next != NULL)
 				list_move_tail(&bf->list, &bf_head);
 
 			ath_tx_rc_status(sc, bf, ts, 1, 1, 0, false);
@@ -463,20 +462,14 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 			}
 		}
 
-		if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) &&
-		    bf_next == NULL) {
-			/*
-			 * Make sure the last desc is reclaimed if it
-			 * not a holding desc.
-			 */
-			if (!bf_last->bf_stale)
-				list_move_tail(&bf->list, &bf_head);
-			else
-				INIT_LIST_HEAD(&bf_head);
-		} else {
-			BUG_ON(list_empty(bf_q));
+		/*
+		 * Make sure the last desc is reclaimed if it
+		 * not a holding desc.
+		 */
+		if (!bf_last->bf_stale || bf_next != NULL)
 			list_move_tail(&bf->list, &bf_head);
-		}
+		else
+			INIT_LIST_HEAD(&bf_head);
 
 		if (!txpending || (tid->state & AGGR_CLEANUP)) {
 			/*
@@ -837,7 +830,7 @@ static void ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
 			bf->bf_state.bf_type &= ~BUF_AGGR;
 			ath9k_hw_clr11n_aggr(sc->sc_ah, bf->bf_desc);
 			ath_buf_set_rate(sc, bf, fi->framelen);
-			ath_tx_txqaddbuf(sc, txq, &bf_q);
+			ath_tx_txqaddbuf(sc, txq, &bf_q, false);
 			continue;
 		}
 
@@ -849,7 +842,7 @@ static void ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
 		/* anchor last desc of aggregate */
 		ath9k_hw_set11n_aggr_last(sc->sc_ah, bf->bf_lastbf->bf_desc);
 
-		ath_tx_txqaddbuf(sc, txq, &bf_q);
+		ath_tx_txqaddbuf(sc, txq, &bf_q, false);
 		TX_STAT_INC(txq->axq_qnum, a_aggr);
 
 	} while (txq->axq_ampdu_depth < ATH_AGGR_MIN_QDEPTH &&
@@ -1085,7 +1078,6 @@ struct ath_txq *ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
 		txq->txq_headidx = txq->txq_tailidx = 0;
 		for (i = 0; i < ATH_TXFIFO_DEPTH; i++)
 			INIT_LIST_HEAD(&txq->txq_fifo[i]);
-		INIT_LIST_HEAD(&txq->txq_fifo_pending);
 	}
 	return &sc->tx.txq[axq_qnum];
 }
@@ -1155,13 +1147,8 @@ static bool bf_is_ampdu_not_probing(struct ath_buf *bf)
     return bf_isampdu(bf) && !(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
 }
 
-/*
- * Drain a given TX queue (could be Beacon or Data)
- *
- * This assumes output has been stopped and
- * we do not need to block ath_tx_tasklet.
- */
-void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq, bool retry_tx)
+static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
+			       struct list_head *list, bool retry_tx)
 {
 	struct ath_buf *bf, *lastbf;
 	struct list_head bf_head;
@@ -1170,93 +1157,63 @@ void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq, bool retry_tx)
 	memset(&ts, 0, sizeof(ts));
 	INIT_LIST_HEAD(&bf_head);
 
-	for (;;) {
-		spin_lock_bh(&txq->axq_lock);
+	while (!list_empty(list)) {
+		bf = list_first_entry(list, struct ath_buf, list);
 
-		if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
-			if (list_empty(&txq->txq_fifo[txq->txq_tailidx])) {
-				txq->txq_headidx = txq->txq_tailidx = 0;
-				spin_unlock_bh(&txq->axq_lock);
-				break;
-			} else {
-				bf = list_first_entry(&txq->txq_fifo[txq->txq_tailidx],
-						      struct ath_buf, list);
-			}
-		} else {
-			if (list_empty(&txq->axq_q)) {
-				txq->axq_link = NULL;
-				spin_unlock_bh(&txq->axq_lock);
-				break;
-			}
-			bf = list_first_entry(&txq->axq_q, struct ath_buf,
-					      list);
-
-			if (bf->bf_stale) {
-				list_del(&bf->list);
-				spin_unlock_bh(&txq->axq_lock);
+		if (bf->bf_stale) {
+			list_del(&bf->list);
 
-				ath_tx_return_buffer(sc, bf);
-				continue;
-			}
+			ath_tx_return_buffer(sc, bf);
+			continue;
 		}
 
 		lastbf = bf->bf_lastbf;
-
-		if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
-			list_cut_position(&bf_head,
-					  &txq->txq_fifo[txq->txq_tailidx],
-					  &lastbf->list);
-			INCR(txq->txq_tailidx, ATH_TXFIFO_DEPTH);
-		} else {
-			/* remove ath_buf's of the same mpdu from txq */
-			list_cut_position(&bf_head, &txq->axq_q, &lastbf->list);
-		}
+		list_cut_position(&bf_head, list, &lastbf->list);
 
 		txq->axq_depth--;
 		if (bf_is_ampdu_not_probing(bf))
 			txq->axq_ampdu_depth--;
-		spin_unlock_bh(&txq->axq_lock);
 
+		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, 0);
+		spin_lock_bh(&txq->axq_lock);
 	}
+}
 
+/*
+ * Drain a given TX queue (could be Beacon or Data)
+ *
+ * This assumes output has been stopped and
+ * we do not need to block ath_tx_tasklet.
+ */
+void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq, bool retry_tx)
+{
 	spin_lock_bh(&txq->axq_lock);
-	txq->axq_tx_inprogress = false;
-	spin_unlock_bh(&txq->axq_lock);
-
 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
-		spin_lock_bh(&txq->axq_lock);
-		while (!list_empty(&txq->txq_fifo_pending)) {
-			bf = list_first_entry(&txq->txq_fifo_pending,
-					      struct ath_buf, list);
-			list_cut_position(&bf_head,
-					  &txq->txq_fifo_pending,
-					  &bf->bf_lastbf->list);
-			spin_unlock_bh(&txq->axq_lock);
+		int idx = txq->txq_tailidx;
 
-			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, 0);
-			spin_lock_bh(&txq->axq_lock);
+		while (!list_empty(&txq->txq_fifo[idx])) {
+			ath_drain_txq_list(sc, txq, &txq->txq_fifo[idx],
+					   retry_tx);
+
+			INCR(idx, ATH_TXFIFO_DEPTH);
 		}
-		spin_unlock_bh(&txq->axq_lock);
+		txq->txq_tailidx = idx;
 	}
 
+	txq->axq_link = NULL;
+	txq->axq_tx_inprogress = false;
+	ath_drain_txq_list(sc, txq, &txq->axq_q, retry_tx);
+
 	/* flush any pending frames if aggregation is enabled */
-	if (sc->sc_flags & SC_OP_TXAGGR) {
-		if (!retry_tx) {
-			spin_lock_bh(&txq->axq_lock);
-			ath_txq_drain_pending_buffers(sc, txq);
-			spin_unlock_bh(&txq->axq_lock);
-		}
-	}
+	if ((sc->sc_flags & SC_OP_TXAGGR) && !retry_tx)
+		ath_txq_drain_pending_buffers(sc, txq);
+
+	spin_unlock_bh(&txq->axq_lock);
 }
 
 bool ath_drain_all_txq(struct ath_softc *sc, bool retry_tx)
@@ -1370,11 +1327,13 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
  * assume the descriptors are already chained together by caller.
  */
 static void ath_tx_txqaddbuf(struct ath_softc *sc, struct ath_txq *txq,
-			     struct list_head *head)
+			     struct list_head *head, bool internal)
 {
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
-	struct ath_buf *bf;
+	struct ath_buf *bf, *bf_last;
+	bool puttxbuf = false;
+	bool edma;
 
 	/*
 	 * Insert the frame on the outbound list and
@@ -1384,51 +1343,49 @@ static void ath_tx_txqaddbuf(struct ath_softc *sc, struct ath_txq *txq,
 	if (list_empty(head))
 		return;
 
+	edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
 	bf = list_first_entry(head, struct ath_buf, list);
+	bf_last = list_entry(head->prev, struct ath_buf, list);
 
 	ath_dbg(common, ATH_DBG_QUEUE,
 		"qnum: %d, txq depth: %d\n", txq->axq_qnum, txq->axq_depth);
 
-	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
-		if (txq->axq_depth >= ATH_TXFIFO_DEPTH) {
-			list_splice_tail_init(head, &txq->txq_fifo_pending);
-			return;
-		}
-		if (!list_empty(&txq->txq_fifo[txq->txq_headidx]))
-			ath_dbg(common, ATH_DBG_XMIT,
-				"Initializing tx fifo %d which is non-empty\n",
-				txq->txq_headidx);
-		INIT_LIST_HEAD(&txq->txq_fifo[txq->txq_headidx]);
-		list_splice_init(head, &txq->txq_fifo[txq->txq_headidx]);
+	if (edma && list_empty(&txq->txq_fifo[txq->txq_headidx])) {
+		list_splice_tail_init(head, &txq->txq_fifo[txq->txq_headidx]);
 		INCR(txq->txq_headidx, ATH_TXFIFO_DEPTH);
-		TX_STAT_INC(txq->axq_qnum, puttxbuf);
-		ath9k_hw_puttxbuf(ah, txq->axq_qnum, bf->bf_daddr);
-		ath_dbg(common, ATH_DBG_XMIT, "TXDP[%u] = %llx (%p)\n",
-			txq->axq_qnum, ito64(bf->bf_daddr), bf->bf_desc);
+		puttxbuf = true;
 	} else {
 		list_splice_tail_init(head, &txq->axq_q);
 
-		if (txq->axq_link == NULL) {
-			TX_STAT_INC(txq->axq_qnum, puttxbuf);
-			ath9k_hw_puttxbuf(ah, txq->axq_qnum, bf->bf_daddr);
-			ath_dbg(common, ATH_DBG_XMIT, "TXDP[%u] = %llx (%p)\n",
-				txq->axq_qnum, ito64(bf->bf_daddr),
-				bf->bf_desc);
-		} else {
-			*txq->axq_link = bf->bf_daddr;
+		if (txq->axq_link) {
+			ath9k_hw_set_desc_link(ah, txq->axq_link, bf->bf_daddr);
 			ath_dbg(common, ATH_DBG_XMIT,
 				"link[%u] (%p)=%llx (%p)\n",
 				txq->axq_qnum, txq->axq_link,
 				ito64(bf->bf_daddr), bf->bf_desc);
-		}
-		ath9k_hw_get_desc_link(ah, bf->bf_lastbf->bf_desc,
-				       &txq->axq_link);
+		} else if (!edma)
+			puttxbuf = true;
+
+		txq->axq_link = bf_last->bf_desc;
+	}
+
+	if (puttxbuf) {
+		TX_STAT_INC(txq->axq_qnum, puttxbuf);
+		ath9k_hw_puttxbuf(ah, txq->axq_qnum, bf->bf_daddr);
+		ath_dbg(common, ATH_DBG_XMIT, "TXDP[%u] = %llx (%p)\n",
+			txq->axq_qnum, ito64(bf->bf_daddr), bf->bf_desc);
+	}
+
+	if (!edma) {
 		TX_STAT_INC(txq->axq_qnum, txstart);
 		ath9k_hw_txstart(ah, txq->axq_qnum);
 	}
-	txq->axq_depth++;
-	if (bf_is_ampdu_not_probing(bf))
-		txq->axq_ampdu_depth++;
+
+	if (!internal) {
+		txq->axq_depth++;
+		if (bf_is_ampdu_not_probing(bf))
+			txq->axq_ampdu_depth++;
+	}
 }
 
 static void ath_tx_send_ampdu(struct ath_softc *sc, struct ath_atx_tid *tid,
@@ -1470,7 +1427,7 @@ static void ath_tx_send_ampdu(struct ath_softc *sc, struct ath_atx_tid *tid,
 	TX_STAT_INC(txctl->txq->axq_qnum, a_queued_hw);
 	bf->bf_lastbf = bf;
 	ath_buf_set_rate(sc, bf, fi->framelen);
-	ath_tx_txqaddbuf(sc, txctl->txq, &bf_head);
+	ath_tx_txqaddbuf(sc, txctl->txq, &bf_head, false);
 }
 
 static void ath_tx_send_normal(struct ath_softc *sc, struct ath_txq *txq,
@@ -1490,7 +1447,7 @@ static void ath_tx_send_normal(struct ath_softc *sc, struct ath_txq *txq,
 	bf->bf_lastbf = bf;
 	fi = get_frame_info(bf->bf_mpdu);
 	ath_buf_set_rate(sc, bf, fi->framelen);
-	ath_tx_txqaddbuf(sc, txq, bf_head);
+	ath_tx_txqaddbuf(sc, txq, bf_head, false);
 	TX_STAT_INC(txq->axq_qnum, queued);
 }
 
@@ -2077,6 +2034,38 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
 	tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
 }
 
+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)
+{
+	int txok;
+
+	txq->axq_depth--;
+	txok = !(ts->ts_status & ATH9K_TXERR_MASK);
+	txq->axq_tx_inprogress = false;
+	if (bf_is_ampdu_not_probing(bf))
+		txq->axq_ampdu_depth--;
+
+	spin_unlock_bh(&txq->axq_lock);
+
+	if (!bf_isampdu(bf)) {
+		/*
+		 * This frame is sent out as a single frame.
+		 * Use hardware retry status for this frame.
+		 */
+		if (ts->ts_status & ATH9K_TXERR_XRETRY)
+			bf->bf_state.bf_type |= BUF_XRETRY;
+		ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok, true);
+		ath_tx_complete_buf(sc, bf, txq, bf_head, ts, txok, 0);
+	} 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);
+}
+
 static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 {
 	struct ath_hw *ah = sc->sc_ah;
@@ -2085,20 +2074,18 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 	struct list_head bf_head;
 	struct ath_desc *ds;
 	struct ath_tx_status ts;
-	int txok;
 	int status;
 
 	ath_dbg(common, ATH_DBG_QUEUE, "tx queue %d (%x), link %p\n",
 		txq->axq_qnum, ath9k_hw_gettxbuf(sc->sc_ah, txq->axq_qnum),
 		txq->axq_link);
 
+	spin_lock_bh(&txq->axq_lock);
 	for (;;) {
-		spin_lock_bh(&txq->axq_lock);
 		if (list_empty(&txq->axq_q)) {
 			txq->axq_link = NULL;
 			if (sc->sc_flags & SC_OP_TXAGGR)
 				ath_txq_schedule(sc, txq);
-			spin_unlock_bh(&txq->axq_lock);
 			break;
 		}
 		bf = list_first_entry(&txq->axq_q, struct ath_buf, list);
@@ -2114,13 +2101,11 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 		bf_held = NULL;
 		if (bf->bf_stale) {
 			bf_held = bf;
-			if (list_is_last(&bf_held->list, &txq->axq_q)) {
-				spin_unlock_bh(&txq->axq_lock);
+			if (list_is_last(&bf_held->list, &txq->axq_q))
 				break;
-			} else {
-				bf = list_entry(bf_held->list.next,
-						struct ath_buf, list);
-			}
+
+			bf = list_entry(bf_held->list.next, struct ath_buf,
+					list);
 		}
 
 		lastbf = bf->bf_lastbf;
@@ -2128,10 +2113,9 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 
 		memset(&ts, 0, sizeof(ts));
 		status = ath9k_hw_txprocdesc(ah, ds, &ts);
-		if (status == -EINPROGRESS) {
-			spin_unlock_bh(&txq->axq_lock);
+		if (status == -EINPROGRESS)
 			break;
-		}
+
 		TX_STAT_INC(txq->axq_qnum, txprocdesc);
 
 		/*
@@ -2145,42 +2129,14 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 			list_cut_position(&bf_head,
 				&txq->axq_q, lastbf->list.prev);
 
-		txq->axq_depth--;
-		txok = !(ts.ts_status & ATH9K_TXERR_MASK);
-		txq->axq_tx_inprogress = false;
-		if (bf_held)
+		if (bf_held) {
 			list_del(&bf_held->list);
-
-		if (bf_is_ampdu_not_probing(bf))
-			txq->axq_ampdu_depth--;
-
-		spin_unlock_bh(&txq->axq_lock);
-
-		if (bf_held)
 			ath_tx_return_buffer(sc, bf_held);
-
-		if (!bf_isampdu(bf)) {
-			/*
-			 * This frame is sent out as a single frame.
-			 * Use hardware retry status for this frame.
-			 */
-			if (ts.ts_status & ATH9K_TXERR_XRETRY)
-				bf->bf_state.bf_type |= BUF_XRETRY;
-			ath_tx_rc_status(sc, bf, &ts, 1, txok ? 0 : 1, txok, true);
 		}
 
-		if (bf_isampdu(bf))
-			ath_tx_complete_aggr(sc, txq, bf, &bf_head, &ts, txok,
-					     true);
-		else
-			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, txok, 0);
-
-		spin_lock_bh(&txq->axq_lock);
-
-		if (sc->sc_flags & SC_OP_TXAGGR)
-			ath_txq_schedule(sc, txq);
-		spin_unlock_bh(&txq->axq_lock);
+		ath_tx_process_buffer(sc, txq, &ts, bf, &bf_head);
 	}
+	spin_unlock_bh(&txq->axq_lock);
 }
 
 static void ath_tx_complete_poll_work(struct work_struct *work)
@@ -2237,17 +2193,16 @@ void ath_tx_tasklet(struct ath_softc *sc)
 
 void ath_tx_edma_tasklet(struct ath_softc *sc)
 {
-	struct ath_tx_status txs;
+	struct ath_tx_status ts;
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_txq *txq;
 	struct ath_buf *bf, *lastbf;
 	struct list_head bf_head;
 	int status;
-	int txok;
 
 	for (;;) {
-		status = ath9k_hw_txprocdesc(ah, NULL, (void *)&txs);
+		status = ath9k_hw_txprocdesc(ah, NULL, (void *)&ts);
 		if (status == -EINPROGRESS)
 			break;
 		if (status == -EIO) {
@@ -2257,12 +2212,13 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
 		}
 
 		/* Skip beacon completions */
-		if (txs.qid == sc->beacon.beaconq)
+		if (ts.qid == sc->beacon.beaconq)
 			continue;
 
-		txq = &sc->tx.txq[txs.qid];
+		txq = &sc->tx.txq[ts.qid];
 
 		spin_lock_bh(&txq->axq_lock);
+
 		if (list_empty(&txq->txq_fifo[txq->txq_tailidx])) {
 			spin_unlock_bh(&txq->axq_lock);
 			return;
@@ -2275,41 +2231,21 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
 		INIT_LIST_HEAD(&bf_head);
 		list_cut_position(&bf_head, &txq->txq_fifo[txq->txq_tailidx],
 				  &lastbf->list);
-		INCR(txq->txq_tailidx, ATH_TXFIFO_DEPTH);
-		txq->axq_depth--;
-		txq->axq_tx_inprogress = false;
-		if (bf_is_ampdu_not_probing(bf))
-			txq->axq_ampdu_depth--;
-		spin_unlock_bh(&txq->axq_lock);
 
-		txok = !(txs.ts_status & ATH9K_TXERR_MASK);
-
-		if (!bf_isampdu(bf)) {
-			if (txs.ts_status & ATH9K_TXERR_XRETRY)
-				bf->bf_state.bf_type |= BUF_XRETRY;
-			ath_tx_rc_status(sc, bf, &txs, 1, txok ? 0 : 1, txok, true);
-		}
-
-		if (bf_isampdu(bf))
-			ath_tx_complete_aggr(sc, txq, bf, &bf_head, &txs,
-					     txok, true);
-		else
-			ath_tx_complete_buf(sc, bf, txq, &bf_head,
-					    &txs, txok, 0);
+		if (list_empty(&txq->txq_fifo[txq->txq_tailidx])) {
+			INCR(txq->txq_tailidx, ATH_TXFIFO_DEPTH);
 
-		spin_lock_bh(&txq->axq_lock);
+			if (!list_empty(&txq->axq_q)) {
+				struct list_head bf_q;
 
-		if (!list_empty(&txq->txq_fifo_pending)) {
-			INIT_LIST_HEAD(&bf_head);
-			bf = list_first_entry(&txq->txq_fifo_pending,
-					      struct ath_buf, list);
-			list_cut_position(&bf_head,
-					  &txq->txq_fifo_pending,
-					  &bf->bf_lastbf->list);
-			ath_tx_txqaddbuf(sc, txq, &bf_head);
-		} else if (sc->sc_flags & SC_OP_TXAGGR)
-			ath_txq_schedule(sc, txq);
+				INIT_LIST_HEAD(&bf_q);
+				txq->axq_link = NULL;
+				list_splice_tail_init(&txq->axq_q, &bf_q);
+				ath_tx_txqaddbuf(sc, txq, &bf_q, true);
+			}
+		}
 
+		ath_tx_process_buffer(sc, txq, &ts, bf, &bf_head);
 		spin_unlock_bh(&txq->axq_lock);
 	}
 }