From: Javier Cardona <javier@xxxxxxxxxxx> This driver reports transmission status to the upper layer (ath5k_tx_frame_completed()) while holding the lock on the transmission queue (txq->lock). Under failure conditions, the mesh stack will attempt to send PERR messages to the previous sender of the failed frame. When that happens the driver will attempt to re-acquire the txq->lock lock causing a deadlock. There are two possible fixes for this, (1) we could defer the transmission of the PERR frame until the lock is released or (2) release the lock before invoking ieee80211_tx_status(). The ath9k driver implements the second approach (see ath_tx_complete() in ath9k/xmit.c) as well as the rt2x00 and b43 drivers. The iwl driver, on the other hand, avoids this problem by invoking ieee80211_tx_status_irqsafe() which effectively defers processing of transmission feedback status. This last approach is the least intrusive is implemented here. Reported by Pedro Larbig (ASPj) --- drivers/net/wireless/ath/ath5k/base.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c index e9ea38d..9b488f9 100644 --- a/drivers/net/wireless/ath/ath5k/base.c +++ b/drivers/net/wireless/ath/ath5k/base.c @@ -1630,7 +1630,7 @@ ath5k_tx_frame_completed(struct ath5k_hw *ah, struct sk_buff *skb, ah->stats.antenna_tx[0]++; /* invalid */ trace_ath5k_tx_complete(ah, skb, txq, ts); - ieee80211_tx_status(ah->hw, skb); + ieee80211_tx_status_irqsafe(ah->hw, skb); } static void -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
