iwlwifi: disable aggregation queue if stopped early

When aggregation is stopped again for some reason
before the queue we selected has drained, we will
currently leak the TX queue and keep it enabled
for aggregation. Normally this doesn't happen, so
the problem is rarely seen.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index e2497e7ba926f7dedcf21a94ea53ddbff382f9c8..a51a7cfa5a14e821290a879a6423f498f21f2f77 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -1036,7 +1036,7 @@ int iwlagn_tx_agg_start(struct iwl_priv *priv, struct ieee80211_vif *vif,
 int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
                       struct ieee80211_sta *sta, u16 tid)
 {
-       int tx_fifo_id, txq_id, sta_id, ssn = -1;
+       int tx_fifo_id, txq_id, sta_id, ssn;
        struct iwl_tid_data *tid_data;
        int write_ptr, read_ptr;
        unsigned long flags;
@@ -1054,21 +1054,26 @@ int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
 
        spin_lock_irqsave(&priv->sta_lock, flags);
 
-       if (priv->stations[sta_id].tid[tid].agg.state ==
-                               IWL_EMPTYING_HW_QUEUE_ADDBA) {
-               IWL_DEBUG_HT(priv, "AGG stop before setup done\n");
-               ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
-               priv->stations[sta_id].tid[tid].agg.state = IWL_AGG_OFF;
-               spin_unlock_irqrestore(&priv->sta_lock, flags);
-               return 0;
-       }
-
-       if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_ON)
-               IWL_WARN(priv, "Stopping AGG while state not ON or starting\n");
-
        tid_data = &priv->stations[sta_id].tid[tid];
        ssn = (tid_data->seq_number & IEEE80211_SCTL_SEQ) >> 4;
        txq_id = tid_data->agg.txq_id;
+
+       switch (priv->stations[sta_id].tid[tid].agg.state) {
+       case IWL_EMPTYING_HW_QUEUE_ADDBA:
+               /*
+                * This can happen if the peer stops aggregation
+                * again before we've had a chance to drain the
+                * queue we selected previously, i.e. before the
+                * session was really started completely.
+                */
+               IWL_DEBUG_HT(priv, "AGG stop before setup done\n");
+               goto turn_off;
+       case IWL_AGG_ON:
+               break;
+       default:
+               IWL_WARN(priv, "Stopping AGG while state not ON or starting\n");
+       }
+
        write_ptr = priv->txq[txq_id].q.write_ptr;
        read_ptr = priv->txq[txq_id].q.read_ptr;
 
@@ -1082,6 +1087,7 @@ int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
        }
 
        IWL_DEBUG_HT(priv, "HW queue is empty\n");
+ turn_off:
        priv->stations[sta_id].tid[tid].agg.state = IWL_AGG_OFF;
 
        /* do not restore/save irqs */