2022-03-25 21:38:29

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH 3/8] mt76: reduce tx queue lock hold time

- call txq dequeue without holding txq lock (locking handled by mac80211)
- disable bh around tx queue schedule

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/mediatek/mt76/tx.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 6b8c9dc80542..830963a65b34 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -463,7 +463,9 @@ mt76_txq_send_burst(struct mt76_phy *phy, struct mt76_queue *q,
ieee80211_get_tx_rates(txq->vif, txq->sta, skb,
info->control.rates, 1);

+ spin_lock(&q->lock);
idx = __mt76_tx_queue_skb(phy, qid, skb, wcid, txq->sta, &stop);
+ spin_unlock(&q->lock);
if (idx < 0)
return idx;

@@ -483,14 +485,18 @@ mt76_txq_send_burst(struct mt76_phy *phy, struct mt76_queue *q,
ieee80211_get_tx_rates(txq->vif, txq->sta, skb,
info->control.rates, 1);

+ spin_lock(&q->lock);
idx = __mt76_tx_queue_skb(phy, qid, skb, wcid, txq->sta, &stop);
+ spin_unlock(&q->lock);
if (idx < 0)
break;

n_frames++;
} while (1);

+ spin_lock(&q->lock);
dev->queue_ops->kick(dev, q);
+ spin_unlock(&q->lock);

return n_frames;
}
@@ -525,8 +531,6 @@ mt76_txq_schedule_list(struct mt76_phy *phy, enum mt76_txq_id qid)
if (wcid && test_bit(MT_WCID_FLAG_PS, &wcid->flags))
continue;

- spin_lock_bh(&q->lock);
-
if (mtxq->send_bar && mtxq->aggr) {
struct ieee80211_txq *txq = mtxq_to_txq(mtxq);
struct ieee80211_sta *sta = txq->sta;
@@ -535,16 +539,12 @@ mt76_txq_schedule_list(struct mt76_phy *phy, enum mt76_txq_id qid)
u8 tid = txq->tid;

mtxq->send_bar = false;
- spin_unlock_bh(&q->lock);
ieee80211_send_bar(vif, sta->addr, tid, agg_ssn);
- spin_lock_bh(&q->lock);
}

if (!mt76_txq_stopped(q))
n_frames = mt76_txq_send_burst(phy, q, mtxq);

- spin_unlock_bh(&q->lock);
-
ieee80211_return_txq(phy->hw, txq, false);

if (unlikely(n_frames < 0))
@@ -563,6 +563,7 @@ void mt76_txq_schedule(struct mt76_phy *phy, enum mt76_txq_id qid)
if (qid >= 4)
return;

+ local_bh_disable();
rcu_read_lock();

do {
@@ -572,6 +573,7 @@ void mt76_txq_schedule(struct mt76_phy *phy, enum mt76_txq_id qid)
} while (len > 0);

rcu_read_unlock();
+ local_bh_enable();
}
EXPORT_SYMBOL_GPL(mt76_txq_schedule);

--
2.35.1