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mt76: introduce q->stopped parameter

PATCH Superseded Lorenzo Bianconi 3 participants 3 messages Feb 27, 2019 – Feb 28, 2019 1 message not in the archive

Subsystems (2)
Arm MediaTek MediaTek MT76 wireless LAN driver

v1 of 2 Superseded Latest is v2 →

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Lorenzo Bianconi

author maintainer
#1 lore raw

PATCH 1/1 mt76: introduce q->stopped parameter

Introduce mt76_queue stopped parameter in order to run ieee80211_wake_queue only when mac80211 queues have been previously stopped and avoid to disable interrupts when it is not necessary.
Move ieee80211_stop_queue out of q->lock critical section

Signed-off-by Lorenzo Bianconi <[email protected]>
---
 drivers/net/wireless/mediatek/mt76/dma.c  |  5 ++++-
 drivers/net/wireless/mediatek/mt76/mt76.h |  1 +
 drivers/net/wireless/mediatek/mt76/tx.c   | 12 +++++++++---
 drivers/net/wireless/mediatek/mt76/usb.c  |  6 +++++-
 4 files changed, 19 insertions(+), 5 deletions(-)
drivers/net/wireless/mediatek/mt76/dma.c +4 -1
index 6eedc0ec7661..99e341cb1f92 100644
@@ -180,7 +180,10 @@ mt76_dma_tx_cleanup(struct mt76_dev *dev, enum mt76_txq_id qid, bool flush)
 	else
 		mt76_dma_sync_idx(dev, q);
 
-	wake = wake && qid < IEEE80211_NUM_ACS && q->queued < q->ndesc - 8;
+	wake = wake && q->stopped &&
+	       qid < IEEE80211_NUM_ACS && q->queued < q->ndesc - 8;
+	if (wake)
+		q->stopped = false;
 
 	if (!q->queued)
 		wake_up(&dev->tx_wait);
drivers/net/wireless/mediatek/mt76/mt76.h +1 -0
index 5dfb0601f101..3152b8c73c4a 100644
@@ -126,6 +126,7 @@ struct mt76_queue {
 	int ndesc;
 	int queued;
 	int buf_size;
+	bool stopped;
 
 	u8 buf_offset;
 	u8 hw_idx;
drivers/net/wireless/mediatek/mt76/tx.c +9 -3
index 5a349fe3e576..97215c3a30d1 100644
@@ -258,8 +258,9 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-	struct mt76_queue *q;
 	int qid = skb_get_queue_mapping(skb);
+	struct mt76_queue *q;
+	bool stop;
 
 	if (WARN_ON(qid >= MT_TXQ_PSD)) {
 		qid = MT_TXQ_BE;

@@ -289,9 +290,14 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
 	dev->queue_ops->tx_queue_skb(dev, q, skb, wcid, sta);
 	dev->queue_ops->kick(dev, q);
 
-	if (q->queued > q->ndesc - 8)
-		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
+	stop = q->queued > q->ndesc - 8 && !q->stopped;
+	if (stop)
+		q->stopped = true;
+
 	spin_unlock_bh(&q->lock);
+
+	if (stop)
+		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
 }
 EXPORT_SYMBOL_GPL(mt76_tx);
drivers/net/wireless/mediatek/mt76/usb.c +5 -1
index ae6ada370597..4c1abd492405 100644
@@ -655,7 +655,11 @@ static void mt76u_tx_tasklet(unsigned long data)
 			spin_lock_bh(&q->lock);
 		}
 		mt76_txq_schedule(dev, q);
-		wake = i < IEEE80211_NUM_ACS && q->queued < q->ndesc - 8;
+
+		wake = q->stopped && q->queued < q->ndesc - 8;
+		if (wake)
+			q->stopped = false;
+
 		if (!q->queued)
 			wake_up(&dev->tx_wait);
Signature · 1 line
2.20.1
#2 lore raw
Quoted 4 lines · Lorenzo Bianconi
drivers/net/wireless/mediatek/mt76/tx.c +0 -0
@@ -289,9 +290,14 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
 	dev->queue_ops->tx_queue_skb(dev, q, skb, wcid, sta);
 	dev->queue_ops->kick(dev, q);

drivers/net/wireless/mediatek/mt76/tx.c mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta, · line 300

Quoted 10 lines
drivers/net/wireless/mediatek/mt76/tx.c +7 -2
-	if (q->queued > q->ndesc - 8)
-		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
+	stop = q->queued > q->ndesc - 8 && !q->stopped;
+	if (stop)
+		q->stopped = true;
+
 	spin_unlock_bh(&q->lock);
+
+	if (stop)
+		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));

I don't think taking this outside of spin_lock section is beneficial. Actually is better to do this faster than slower to prevent enqueue frames by mac80211 and then dropped them due to lack of space in mt76 queue.

Stanislaw

#3 lore raw
Quoted 5 lines · Lorenzo Bianconi
Quoted 4 lines
drivers/net/wireless/mediatek/mt76/tx.c +0 -0
@@ -289,9 +290,14 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
 	dev->queue_ops->tx_queue_skb(dev, q, skb, wcid, sta);
 	dev->queue_ops->kick(dev, q);
Quoted 15 lines

drivers/net/wireless/mediatek/mt76/tx.c mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta, · line 300

Quoted 10 lines
drivers/net/wireless/mediatek/mt76/tx.c +7 -2
-	if (q->queued > q->ndesc - 8)
-		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
+	stop = q->queued > q->ndesc - 8 && !q->stopped;
+	if (stop)
+		q->stopped = true;
+
 	spin_unlock_bh(&q->lock);
+
+	if (stop)
+		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));

I don't think taking this outside of spin_lock section is beneficial. Actually is better to do this faster than slower to prevent enqueue frames by mac80211 and then dropped them due to lack of space in mt76 queue.

ack, I will send a v2 moving it back.

Regards,
Lorenzo

Quoted 2 lines

Stanislaw