Commit 5342758d authored by Felix Fietkau's avatar Felix Fietkau
Browse files

mt76: mt7915: stop queues when running out of tx tokens 



Avoids packet drops under load with lots of stations

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent 90d494c9

drivers/net/wireless/mediatek/mt76/mt7915/init.c

+1 −0
Original line number Diff line number Diff line
@@ -690,6 +690,7 @@ void mt7915_unregister_device(struct mt7915_dev *dev) 
			ieee80211_free_txskb(hw, txwi->skb);

		}

		mt76_put_txwi(&dev->mt76, txwi);

		dev->token_count--;

	}

	spin_unlock_bh(&dev->token_lock);

	idr_destroy(&dev->token);

drivers/net/wireless/mediatek/mt76/mt7915/mac.c

+39 −0
Original line number Diff line number Diff line
@@ -906,6 +906,26 @@ void mt7915_mac_write_txwi(struct mt7915_dev *dev, __le32 *txwi, 
		mt7915_mac_write_txwi_tm(dev, mphy, txwi, skb);

}



static void

mt7915_set_tx_blocked(struct mt7915_dev *dev, bool blocked)

{

	struct mt76_phy *mphy = &dev->mphy, *mphy2 = dev->mt76.phy2;

	struct mt76_queue *q, *q2 = NULL;



	q = mphy->q_tx[0];

	if (blocked == q->blocked)

		return;



	q->blocked = blocked;

	if (mphy2) {

		q2 = mphy2->q_tx[0];

		q2->blocked = blocked;

	}



	if (!blocked)

		mt76_worker_schedule(&dev->mt76.tx_worker);

}



int mt7915_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,

			  enum mt76_txq_id qid, struct mt76_wcid *wcid,

			  struct ieee80211_sta *sta,
@@ -962,7 +982,13 @@ int mt7915_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr, 


	spin_lock_bh(&dev->token_lock);

	id = idr_alloc(&dev->token, t, 0, MT7915_TOKEN_SIZE, GFP_ATOMIC);

	if (id >= 0)

		dev->token_count++;



	if (dev->token_count >= MT7915_TOKEN_SIZE - MT7915_TOKEN_FREE_THR)

		mt7915_set_tx_blocked(dev, true);

	spin_unlock_bh(&dev->token_lock);



	if (id < 0)

		return id;
@@ -1071,6 +1097,7 @@ void mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb) 
	LIST_HEAD(free_list);

	struct sk_buff *tmp;

	u8 i, count;

	bool wake = false;



	/* clean DMA queues and unmap buffers first */

	mt76_queue_tx_cleanup(dev, dev->mphy.q_tx[MT_TXQ_PSD], false);
@@ -1123,6 +1150,11 @@ void mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb) 


		spin_lock_bh(&dev->token_lock);

		txwi = idr_remove(&dev->token, msdu);

		if (txwi)

			dev->token_count--;

		if (dev->token_count < MT7915_TOKEN_SIZE - MT7915_TOKEN_FREE_THR &&

		    dev->mphy.q_tx[0]->blocked)

			wake = true;

		spin_unlock_bh(&dev->token_lock);



		if (!txwi)
@@ -1153,6 +1185,13 @@ void mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb) 
	}



	mt7915_mac_sta_poll(dev);



	if (wake) {

		spin_lock_bh(&dev->token_lock);

		mt7915_set_tx_blocked(dev, false);

		spin_unlock_bh(&dev->token_lock);

	}



	mt76_worker_schedule(&dev->mt76.tx_worker);



	napi_consume_skb(skb, 1);

drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h

+2 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 


#define MT7915_EEPROM_SIZE		3584

#define MT7915_TOKEN_SIZE		8192

#define MT7915_TOKEN_FREE_THR		64



#define MT7915_CFEND_RATE_DEFAULT	0x49	/* OFDM 24M */

#define MT7915_CFEND_RATE_11B		0x03	/* 11B LP, 11M */
@@ -161,6 +162,7 @@ struct mt7915_dev { 
	u32 hw_pattern;



	spinlock_t token_lock;

	int token_count;

	struct idr token;



	s8 **rate_power; /* TODO: use mt76_rate_power */