From: Felix Fietkau <nbd@nbd.name>
To: linux-wireless@vger.kernel.org
Subject: [PATCH v2 2/3] mt76: mt7915: stop queues when running out of tx tokens
Date: Fri, 4 Dec 2020 14:17:36 +0100 [thread overview]
Message-ID: <20201204131737.41086-2-nbd@nbd.name> (raw)
In-Reply-To: <20201204131737.41086-1-nbd@nbd.name>
Avoids packet drops under load with lots of stations
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
.../net/wireless/mediatek/mt76/mt7915/init.c | 1 +
.../net/wireless/mediatek/mt76/mt7915/mac.c | 39 +++++++++++++++++++
.../wireless/mediatek/mt76/mt7915/mt7915.h | 2 +
3 files changed, 42 insertions(+)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
index ff29a8090739..ed4635bd151a 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
@@ -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);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
index a7fa6fffffff..71714b22188a 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
@@ -918,6 +918,26 @@ 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,
@@ -974,7 +994,13 @@ 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;
@@ -1083,6 +1109,7 @@ 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);
@@ -1135,6 +1162,11 @@ 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)
@@ -1165,6 +1197,13 @@ 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);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h b/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h
index 30e53a0f01fb..0339abf360d3 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h
@@ -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 */
--
2.28.0
next prev parent reply other threads:[~2020-12-04 13:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-04 13:17 [PATCH v2 1/3] mt76: improve tx queue stop/wake Felix Fietkau
2020-12-04 13:17 ` Felix Fietkau [this message]
2020-12-04 13:17 ` [PATCH v2 3/3] mt76: attempt to free up more room when filling the tx queue Felix Fietkau
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