diff options
| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2017-12-19 14:33:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-13 20:48:11 +0300 |
| commit | c8fed0d73cad36fd01cbd4fc8c18c4307b7bf95c (patch) | |
| tree | c5b3efbefc2135ae10dab41e689605149835e902 /drivers/net/wireless | |
| parent | 29a63b0372f0fd6d8edc68829e02fe63ffd2735b (diff) | |
| download | linux-c8fed0d73cad36fd01cbd4fc8c18c4307b7bf95c.tar.xz | |
rt2x00: do not pause queue unconditionally on error path
[ Upstream commit 6dd80efd75ce7c2dbd9f117cf585ee2b33a42ee1 ]
Pausing queue without checking threshold is racy with txdone path.
Moreover we do not need pause queue on any error, but only if queue
is full - in case when we send RTS frame ( other cases of almost full
queue are already handled in rt2x00queue_write_tx_frame() ).
Patch fixes of theoretically possible problem of pausing empty
queue.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/wireless')
| -rw-r--r-- | drivers/net/wireless/ralink/rt2x00/rt2x00mac.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2x00mac.c b/drivers/net/wireless/ralink/rt2x00/rt2x00mac.c index 13da95a24cf7..987c7c4f43cd 100644 --- a/drivers/net/wireless/ralink/rt2x00/rt2x00mac.c +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00mac.c @@ -142,15 +142,25 @@ void rt2x00mac_tx(struct ieee80211_hw *hw, if (!rt2x00dev->ops->hw->set_rts_threshold && (tx_info->control.rates[0].flags & (IEEE80211_TX_RC_USE_RTS_CTS | IEEE80211_TX_RC_USE_CTS_PROTECT))) { - if (rt2x00queue_available(queue) <= 1) - goto exit_fail; + if (rt2x00queue_available(queue) <= 1) { + /* + * Recheck for full queue under lock to avoid race + * conditions with rt2x00lib_txdone(). + */ + spin_lock(&queue->tx_lock); + if (rt2x00queue_threshold(queue)) + rt2x00queue_pause_queue(queue); + spin_unlock(&queue->tx_lock); + + goto exit_free_skb; + } if (rt2x00mac_tx_rts_cts(rt2x00dev, queue, skb)) - goto exit_fail; + goto exit_free_skb; } if (unlikely(rt2x00queue_write_tx_frame(queue, skb, control->sta, false))) - goto exit_fail; + goto exit_free_skb; /* * Pausing queue has to be serialized with rt2x00lib_txdone(). Note @@ -164,10 +174,6 @@ void rt2x00mac_tx(struct ieee80211_hw *hw, return; - exit_fail: - spin_lock(&queue->tx_lock); - rt2x00queue_pause_queue(queue); - spin_unlock(&queue->tx_lock); exit_free_skb: ieee80211_free_txskb(hw, skb); } |