* [PATCH 1/4] mt76: add missing locking around ampdu action
@ 2019-10-07 14:10 Felix Fietkau
2019-10-07 14:10 ` [PATCH 2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop Felix Fietkau
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Felix Fietkau @ 2019-10-07 14:10 UTC (permalink / raw)
To: linux-wireless
This is needed primarily to avoid races in dealing with rx aggregation
related data structures
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/net/wireless/mediatek/mt76/mt7603/main.c | 2 ++
drivers/net/wireless/mediatek/mt76/mt7615/main.c | 2 ++
drivers/net/wireless/mediatek/mt76/mt76x02_util.c | 2 ++
3 files changed, 6 insertions(+)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/main.c b/drivers/net/wireless/mediatek/mt76/mt7603/main.c
index 180eb6bb781a..c4dac556fb2e 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/main.c
@@ -569,6 +569,7 @@ mt7603_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
mtxq = (struct mt76_txq *)txq->drv_priv;
+ mutex_lock(&dev->mt76.mutex);
switch (action) {
case IEEE80211_AMPDU_RX_START:
mt76_rx_aggr_start(&dev->mt76, &msta->wcid, tid, ssn,
@@ -598,6 +599,7 @@ mt7603_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
break;
}
+ mutex_unlock(&dev->mt76.mutex);
return 0;
}
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/main.c b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
index 942076b6d1ad..d9f4d425424c 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
@@ -483,6 +483,7 @@ mt7615_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
mtxq = (struct mt76_txq *)txq->drv_priv;
+ mutex_lock(&dev->mt76.mutex);
switch (action) {
case IEEE80211_AMPDU_RX_START:
mt76_rx_aggr_start(&dev->mt76, &msta->wcid, tid, ssn,
@@ -513,6 +514,7 @@ mt7615_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
break;
}
+ mutex_unlock(&dev->mt76.mutex);
return 0;
}
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_util.c b/drivers/net/wireless/mediatek/mt76/mt76x02_util.c
index f5695ebdb225..bb7edf288597 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_util.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_util.c
@@ -372,6 +372,7 @@ int mt76x02_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
mtxq = (struct mt76_txq *)txq->drv_priv;
+ mutex_lock(&dev->mt76.mutex);
switch (action) {
case IEEE80211_AMPDU_RX_START:
mt76_rx_aggr_start(&dev->mt76, &msta->wcid, tid,
@@ -401,6 +402,7 @@ int mt76x02_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
break;
}
+ mutex_unlock(&dev->mt76.mutex);
return 0;
}
--
2.17.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop
2019-10-07 14:10 [PATCH 1/4] mt76: add missing locking around ampdu action Felix Fietkau
@ 2019-10-07 14:10 ` Felix Fietkau
2019-10-07 14:10 ` [PATCH 3/4] mt76: fix aggregation stop issue Felix Fietkau
2019-10-07 14:10 ` [PATCH 4/4] mt76: avoid enabling interrupt if NAPI poll is still pending Felix Fietkau
2 siblings, 0 replies; 4+ messages in thread
From: Felix Fietkau @ 2019-10-07 14:10 UTC (permalink / raw)
To: linux-wireless
A rcu read locked section is not allowed to sleep, and the rcu lock here
isn't actually necessary, because we're holding dev->mutex.
Fixes an issue when the tid work item is still running while freeing
a station or stopping the aggregation session
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/net/wireless/mediatek/mt76/agg-rx.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/agg-rx.c b/drivers/net/wireless/mediatek/mt76/agg-rx.c
index 2276fd4e9ec3..b05d439dca3b 100644
--- a/drivers/net/wireless/mediatek/mt76/agg-rx.c
+++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c
@@ -277,17 +277,13 @@ static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid)
void mt76_rx_aggr_stop(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno)
{
- struct mt76_rx_tid *tid;
-
- rcu_read_lock();
+ struct mt76_rx_tid *tid = NULL;
- tid = rcu_dereference(wcid->aggr[tidno]);
+ rcu_swap_protected(wcid->aggr[tidno], tid,
+ lockdep_is_held(&dev->mutex));
if (tid) {
- rcu_assign_pointer(wcid->aggr[tidno], NULL);
mt76_rx_aggr_shutdown(dev, tid);
kfree_rcu(tid, rcu_head);
}
-
- rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(mt76_rx_aggr_stop);
--
2.17.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 3/4] mt76: fix aggregation stop issue
2019-10-07 14:10 [PATCH 1/4] mt76: add missing locking around ampdu action Felix Fietkau
2019-10-07 14:10 ` [PATCH 2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop Felix Fietkau
@ 2019-10-07 14:10 ` Felix Fietkau
2019-10-07 14:10 ` [PATCH 4/4] mt76: avoid enabling interrupt if NAPI poll is still pending Felix Fietkau
2 siblings, 0 replies; 4+ messages in thread
From: Felix Fietkau @ 2019-10-07 14:10 UTC (permalink / raw)
To: linux-wireless
Cancel the workqueue after the tid has been cleaned up, in order to
avoid a possible rescheduling from within the work function.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/net/wireless/mediatek/mt76/agg-rx.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/agg-rx.c b/drivers/net/wireless/mediatek/mt76/agg-rx.c
index b05d439dca3b..53b5a4b2dcc5 100644
--- a/drivers/net/wireless/mediatek/mt76/agg-rx.c
+++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c
@@ -130,8 +130,10 @@ mt76_rx_aggr_check_ctl(struct sk_buff *skb, struct sk_buff_head *frames)
return;
spin_lock_bh(&tid->lock);
- mt76_rx_aggr_release_frames(tid, frames, seqno);
- mt76_rx_aggr_release_head(tid, frames);
+ if (!tid->stopped) {
+ mt76_rx_aggr_release_frames(tid, frames, seqno);
+ mt76_rx_aggr_release_head(tid, frames);
+ }
spin_unlock_bh(&tid->lock);
}
@@ -257,8 +259,6 @@ static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid)
u8 size = tid->size;
int i;
- cancel_delayed_work_sync(&tid->reorder_work);
-
spin_lock_bh(&tid->lock);
tid->stopped = true;
@@ -273,6 +273,8 @@ static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid)
}
spin_unlock_bh(&tid->lock);
+
+ cancel_delayed_work_sync(&tid->reorder_work);
}
void mt76_rx_aggr_stop(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno)
--
2.17.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 4/4] mt76: avoid enabling interrupt if NAPI poll is still pending
2019-10-07 14:10 [PATCH 1/4] mt76: add missing locking around ampdu action Felix Fietkau
2019-10-07 14:10 ` [PATCH 2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop Felix Fietkau
2019-10-07 14:10 ` [PATCH 3/4] mt76: fix aggregation stop issue Felix Fietkau
@ 2019-10-07 14:10 ` Felix Fietkau
2 siblings, 0 replies; 4+ messages in thread
From: Felix Fietkau @ 2019-10-07 14:10 UTC (permalink / raw)
To: linux-wireless
if napi_complete() returns false, it means that polling is still pending.
Interrupts should not fire until the polling is no longer scheduled
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/net/wireless/mediatek/mt76/dma.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index e2ce59b260c1..4da7cffbab29 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -537,10 +537,8 @@ mt76_dma_rx_poll(struct napi_struct *napi, int budget)
rcu_read_unlock();
- if (done < budget) {
- napi_complete(napi);
+ if (done < budget && napi_complete(napi))
dev->drv->rx_poll_complete(dev, qid);
- }
return done;
}
--
2.17.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-10-07 14:10 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-10-07 14:10 [PATCH 1/4] mt76: add missing locking around ampdu action Felix Fietkau
2019-10-07 14:10 ` [PATCH 2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop Felix Fietkau
2019-10-07 14:10 ` [PATCH 3/4] mt76: fix aggregation stop issue Felix Fietkau
2019-10-07 14:10 ` [PATCH 4/4] mt76: avoid enabling interrupt if NAPI poll is still pending Felix Fietkau
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