mt76: reduce q->lock hold time

BugLink: https://bugs.launchpad.net/bugs/1929455
[ Upstream commit 2fbcdb4386dda0a911b5485b33468540716251f8 ]

Instead of holding it for the duration of an entire station schedule run,
which can block out competing tasks for a significant amount of time,
only hold it for scheduling one batch of packets for one station.
Improves responsiveness under load

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 25627e70bdad29a453c8002d45e462db814d0b86..d5953223d7cfa49711b08dbbe1467964b7c85c6f 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -454,7 +454,6 @@ mt76_txq_schedule_list(struct mt76_phy *phy, enum mt76_txq_id qid)
        struct mt76_wcid *wcid;
        int ret = 0;
 
-       spin_lock_bh(&q->lock);
        while (1) {
                if (test_bit(MT76_STATE_PM, &phy->state) ||
                    test_bit(MT76_RESET, &phy->state)) {
@@ -464,14 +463,9 @@ mt76_txq_schedule_list(struct mt76_phy *phy, enum mt76_txq_id qid)
 
                if (dev->queue_ops->tx_cleanup &&
                    q->queued + 2 * MT_TXQ_FREE_THR >= q->ndesc) {
-                       spin_unlock_bh(&q->lock);
                        dev->queue_ops->tx_cleanup(dev, q, false);
-                       spin_lock_bh(&q->lock);
                }
 
-               if (mt76_txq_stopped(q))
-                       break;
-
                txq = ieee80211_next_txq(phy->hw, qid);
                if (!txq)
                        break;
@@ -481,6 +475,8 @@ 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;
@@ -494,10 +490,13 @@ mt76_txq_schedule_list(struct mt76_phy *phy, enum mt76_txq_id qid)
                        spin_lock_bh(&q->lock);
                }
 
-               ret += mt76_txq_send_burst(phy, q, mtxq);
+               if (!mt76_txq_stopped(q))
+                       ret += mt76_txq_send_burst(phy, q, mtxq);
+
+               spin_unlock_bh(&q->lock);
+
                ieee80211_return_txq(phy->hw, txq, false);
        }
-       spin_unlock_bh(&q->lock);
 
        return ret;
 }