iwlagn: move the check_empty logic to the transport layer

This logic is responsible to tell mac80211 when the HW queues are
empty and the BA session can be started / torn down.

Fix a bug on the way:
When the the Tx BA session is stopped and the HW queues aren't empty,
we stop the SW queue to drain the HW queue and then switch to the
legacy HW queue. This is the IWL_EMPTYING_HW_QUEUE_DELBA state.

While in this state, we never wake the SW queue, even when the HW
queue is almost empty, since we need to drain it completely. Look
at iwl_trans_pcie_reclaim regarding this.

Once the HW queue is really empty, we must wake the SW queue in order
to get traffic to the legacy queue.
This step was missing leading to an odd situation were the traffic
would just stall after we tore down a Tx BA session while the HW
queue was not empty.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 61 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index e91a0ee1189b..45eb45af5953 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -477,43 +477,6 @@ int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
 	return 0;
 }
 
-static int iwlagn_txq_check_empty(struct iwl_priv *priv,
-			   int sta_id, u8 tid, int txq_id)
-{
-	struct iwl_queue *q = &priv->txq[txq_id].q;
-	u8 *addr = priv->stations[sta_id].sta.sta.addr;
-	struct iwl_tid_data *tid_data = &priv->shrd->tid_data[sta_id][tid];
-	struct iwl_rxon_context *ctx;
-
-	ctx = &priv->contexts[priv->stations[sta_id].ctxid];
-
-	lockdep_assert_held(&priv->shrd->sta_lock);
-
-	switch (priv->shrd->tid_data[sta_id][tid].agg.state) {
-	case IWL_EMPTYING_HW_QUEUE_DELBA:
-		/* We are reclaiming the last packet of the */
-		/* aggregated HW queue */
-		if ((txq_id  == tid_data->agg.txq_id) &&
-		    (q->read_ptr == q->write_ptr)) {
-			IWL_DEBUG_HT(priv, "HW queue empty: continue DELBA flow\n");
-			iwl_trans_txq_agg_disable(trans(priv), txq_id);
-			tid_data->agg.state = IWL_AGG_OFF;
-			ieee80211_stop_tx_ba_cb_irqsafe(ctx->vif, addr, tid);
-		}
-		break;
-	case IWL_EMPTYING_HW_QUEUE_ADDBA:
-		/* We are reclaiming the last packet of the queue */
-		if (tid_data->tfds_in_queue == 0) {
-			IWL_DEBUG_HT(priv, "HW queue empty: continue ADDBA flow\n");
-			tid_data->agg.state = IWL_AGG_ON;
-			ieee80211_start_tx_ba_cb_irqsafe(ctx->vif, addr, tid);
-		}
-		break;
-	}
-
-	return 0;
-}
-
 static void iwlagn_non_agg_tx_status(struct iwl_priv *priv,
 				     struct iwl_rxon_context *ctx,
 				     const u8 *addr1)
@@ -724,21 +687,6 @@ static inline u32 iwlagn_get_scd_ssn(struct iwlagn_tx_resp *tx_resp)
 			    tx_resp->frame_count) & MAX_SN;
 }
 
-static void iwl_free_tfds_in_queue(struct iwl_priv *priv,
-			    int sta_id, int tid, int freed)
-{
-	lockdep_assert_held(&priv->shrd->sta_lock);
-
-	if (priv->shrd->tid_data[sta_id][tid].tfds_in_queue >= freed)
-		priv->shrd->tid_data[sta_id][tid].tfds_in_queue -= freed;
-	else {
-		IWL_DEBUG_TX(priv, "free more than tfds_in_queue (%u:%d)\n",
-			priv->shrd->tid_data[sta_id][tid].tfds_in_queue,
-			freed);
-		priv->shrd->tid_data[sta_id][tid].tfds_in_queue = 0;
-	}
-}
-
 static void iwlagn_count_tx_err_status(struct iwl_priv *priv, u16 status)
 {
 	status &= TX_STATUS_MSK;
@@ -889,7 +837,8 @@ void iwlagn_rx_reply_tx(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
 
 		__skb_queue_head_init(&skbs);
 		/*we can free until ssn % q.n_bd not inclusive */
-		iwl_trans_reclaim(trans(priv), txq_id, ssn, status, &skbs);
+		iwl_trans_reclaim(trans(priv), sta_id, tid, txq_id,
+				  ssn, status, &skbs);
 		freed = 0;
 		while (!skb_queue_empty(&skbs)) {
 			skb = __skb_dequeue(&skbs);
@@ -939,9 +888,6 @@ void iwlagn_rx_reply_tx(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
 		}
 
 		WARN_ON(!is_agg && freed != 1);
-
-		iwl_free_tfds_in_queue(priv, sta_id, tid, freed);
-		iwlagn_txq_check_empty(priv, sta_id, tid, txq_id);
 	}
 
 	iwl_check_abort_status(priv, tx_resp->frame_count, status);
@@ -1050,8 +996,8 @@ void iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
 	/* Release all TFDs before the SSN, i.e. all TFDs in front of
 	 * block-ack window (we assume that they've been successfully
 	 * transmitted ... if not, it's too late anyway). */
-	iwl_trans_reclaim(trans(priv), scd_flow, ba_resp_scd_ssn, 0,
-			  &reclaimed_skbs);
+	iwl_trans_reclaim(trans(priv), sta_id, tid, scd_flow, ba_resp_scd_ssn,
+			  0, &reclaimed_skbs);
 	freed = 0;
 	while (!skb_queue_empty(&reclaimed_skbs)) {
 
@@ -1082,8 +1028,5 @@ void iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
 		ieee80211_tx_status_irqsafe(priv->hw, skb);
 	}
 
-	iwl_free_tfds_in_queue(priv, sta_id, tid, freed);
-	iwlagn_txq_check_empty(priv, sta_id, tid, scd_flow);
-
 	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);
 }