From d94cc81d398065ad15eee6850cb7a6c63753d7e6 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 7 Oct 2019 15:30:18 +0200 Subject: [PATCH] mt76: drop rcu read lock in mt76_rx_aggr_stop 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 --- agg-rx.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/agg-rx.c b/agg-rx.c index f0c397c5..53b5a4b2 100644 --- a/agg-rx.c +++ b/agg-rx.c @@ -279,17 +279,13 @@ 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; + struct mt76_rx_tid *tid = NULL; - rcu_read_lock(); - - 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);