2011-11-20 05:30:59

by Nikolay Martynov

Subject: [PATCH v2] ath9k: Improve ath_tx_aggr_stop to avoid TID stuck in cleanup state.

From: kolya <[email protected]>

When tx agg is being stopped TID is flushed using ath_tx_flush_tid. It is possible that ath_tx_flush_tid completelly flushes TID (if all packets in this TID have already been retried). If this happened ath_tx_aggr_stop would leave TID in cleanup state permanently. Fix this by making ath_tx_flush_tid remove AGGR_ADDBA_COMPLETE and AGGR_CLEANUP flags from TID status if TID is empty.
---
drivers/net/wireless/ath/ath9k/xmit.c | 13 ++++++-------
1 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 55d077e..80639e3 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -179,6 +179,11 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
spin_lock_bh(&txq->axq_lock);
}

+ if (tid->baw_head == tid->baw_tail) {
+ tid->state &= ~AGGR_ADDBA_COMPLETE;
+ tid->state &= ~AGGR_CLEANUP;
+ }
+
spin_unlock_bh(&txq->axq_lock);
}

@@ -556,15 +561,9 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
spin_unlock_bh(&txq->axq_lock);
}

- if (tid->state & AGGR_CLEANUP) {
+ if (tid->state & AGGR_CLEANUP)
ath_tx_flush_tid(sc, tid);

- if (tid->baw_head == tid->baw_tail) {
- tid->state &= ~AGGR_ADDBA_COMPLETE;
- tid->state &= ~AGGR_CLEANUP;
- }
- }
-
rcu_read_unlock();

if (needreset) {
--
1.7.4.1

2011-11-21 19:45:33

by John W. Linville

Subject: Re: [PATCH v2] ath9k: Improve ath_tx_aggr_stop to avoid TID stuck in cleanup state.

On Sun, Nov 20, 2011 at 12:30:35AM -0500, Nikolay Martynov wrote:
> From: kolya <[email protected]>
>
> When tx agg is being stopped TID is flushed using ath_tx_flush_tid. It is possible that ath_tx_flush_tid completelly flushes TID (if all packets in this TID have already been retried). If this happened ath_tx_aggr_stop would leave TID in cleanup state permanently. Fix this by making ath_tx_flush_tid remove AGGR_ADDBA_COMPLETE and AGGR_CLEANUP flags from TID status if TID is empty.

Please follow the suggestions Kalle made about your patch. Please also
include a Signed-off-by line.

John
--
John W. Linville Someday the world will need a hero, and you
[email protected] might be all we have. Be ready.