diff mbox series

[2/4] mt76: drop rcu read lock in mt76_rx_aggr_stop

Message ID 20191007141022.75184-2-nbd@nbd.name (mailing list archive)
State Accepted
Delegated to: Felix Fietkau
Headers show
Series [1/4] mt76: add missing locking around ampdu action | expand

Commit Message

Felix Fietkau Oct. 7, 2019, 2:10 p.m. UTC 
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 mbox series

Patch

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);