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| author |   Stanislaw Gruszka <sgruszka@redhat.com> | 2012-03-09 12:39:54 +0100 |
|---|---|---|
| committer |   John W. Linville <linville@tuxdriver.com> | 2012-03-12 14:00:17 -0400 |
| commit | 3780d038fdf4b5ef26ead10b0604ab1f46dd9510 (patch) | |
| tree | 26dd6359017398e1b61e51ae05a24a98d96e9fe1 /drivers/net/wireless/rt2x00/rt2x00queue.c | |
| parent | iwl3945: fix possible il->txq NULL pointer dereference in delayed works (diff) | |
| download | linux-dev-3780d038fdf4b5ef26ead10b0604ab1f46dd9510.tar.xz linux-dev-3780d038fdf4b5ef26ead10b0604ab1f46dd9510.zip | |
rt2x00: fix random stalls
Is possible that we stop queue and then do not wake up it again,
especially when packets are transmitted fast. That can be easily
reproduced with modified tx queue entry_num to some small value e.g. 16.
If mac80211 already hold local->queue_stop_reason_lock, then we can wait
on that lock in both rt2x00queue_pause_queue() and
rt2x00queue_unpause_queue(). After drooping ->queue_stop_reason_lock
is possible that __ieee80211_wake_queue() will be performed before
__ieee80211_stop_queue(), hence we stop queue and newer wake up it
again.
Another race condition is possible when between rt2x00queue_threshold()
check and rt2x00queue_pause_queue() we will process all pending tx
buffers on different cpu. This might happen if for example interrupt
will be triggered on cpu performing rt2x00mac_tx().
To prevent race conditions serialize pause/unpause by queue->tx_lock.
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to '')
| -rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00queue.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c index 5adfb3eab9cd..9b1b2b7a7807 100644 --- a/drivers/net/wireless/rt2x00/rt2x00queue.c +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c @@ -619,6 +619,9 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb, else if (test_bit(REQUIRE_DMA, &queue->rt2x00dev->cap_flags)) rt2x00queue_align_frame(skb); + /* + * That function must be called with bh disabled. + */ spin_lock(&queue->tx_lock); if (unlikely(rt2x00queue_full(queue))) { |