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Commit 65f3ddcd authored by Nishant Sarmukadam's avatar Nishant Sarmukadam Committed by John W. Linville
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mwl8k: Initiate BA sessions 



Specifically, handle ampdu_action and attempt to start a BA
session on receiving the first qos packet from mac80211 for
transmission to a HT sta.  While the BA session is being created,
all the packets belonging to that stream will be dropped to
prevent sequence number mismatch at the recipient.

Contains contributions from:
Yogesh Powar <yogeshp@marvell.com>
Pradeep Nemavat <pnemavat@marvell.com>
Brian Cavagnolo <brian@cozybit.com>

Signed-off-by: default avatarBrian Cavagnolo <brian@cozybit.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent ac109fd0

drivers/net/wireless/mwl8k.c

+187 −7
Original line number Diff line number Diff line
@@ -1577,7 +1577,8 @@ mwl8k_txq_reclaim(struct ieee80211_hw *hw, int index, int limit, int force) 
		processed++;

	}



	if (processed && priv->radio_on && !mutex_is_locked(&priv->fw_mutex))

	if (index < MWL8K_TX_WMM_QUEUES && processed && priv->radio_on &&

	    !mutex_is_locked(&priv->fw_mutex))

		ieee80211_wake_queue(hw, index);



	return processed;
@@ -1677,6 +1678,7 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb) 
	struct mwl8k_priv *priv = hw->priv;

	struct ieee80211_tx_info *tx_info;

	struct mwl8k_vif *mwl8k_vif;

	struct ieee80211_sta *sta;

	struct ieee80211_hdr *wh;

	struct mwl8k_tx_queue *txq;

	struct mwl8k_tx_desc *tx;
@@ -1684,6 +1686,10 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb) 
	u32 txstatus;

	u8 txdatarate;

	u16 qos;

	int txpriority;

	u8 tid = 0;

	struct mwl8k_ampdu_stream *stream = NULL;

	bool start_ba_session = false;



	wh = (struct ieee80211_hdr *)skb->data;

	if (ieee80211_is_data_qos(wh->frame_control))
@@ -1699,6 +1705,7 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb) 
	wh = &((struct mwl8k_dma_data *)skb->data)->wh;



	tx_info = IEEE80211_SKB_CB(skb);

	sta = tx_info->control.sta;

	mwl8k_vif = MWL8K_VIF(tx_info->control.vif);



	if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
@@ -1726,12 +1733,70 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb) 
			qos |= MWL8K_QOS_ACK_POLICY_NORMAL;

	}



	txpriority = index;



	if (ieee80211_is_data_qos(wh->frame_control) &&

	    skb->protocol != cpu_to_be16(ETH_P_PAE) &&

	    sta->ht_cap.ht_supported && priv->ap_fw) {

		tid = qos & 0xf;

		spin_lock(&priv->stream_lock);

		stream = mwl8k_lookup_stream(hw, sta->addr, tid);

		if (stream != NULL) {

			if (stream->state == AMPDU_STREAM_ACTIVE) {

				txpriority = stream->txq_idx;

				index = stream->txq_idx;

			} else if (stream->state == AMPDU_STREAM_NEW) {

				/* We get here if the driver sends us packets

				 * after we've initiated a stream, but before

				 * our ampdu_action routine has been called

				 * with IEEE80211_AMPDU_TX_START to get the SSN

				 * for the ADDBA request.  So this packet can

				 * go out with no risk of sequence number

				 * mismatch.  No special handling is required.

				 */

			} else {

				/* Drop packets that would go out after the

				 * ADDBA request was sent but before the ADDBA

				 * response is received.  If we don't do this,

				 * the recipient would probably receive it

				 * after the ADDBA request with SSN 0.  This

				 * will cause the recipient's BA receive window

				 * to shift, which would cause the subsequent

				 * packets in the BA stream to be discarded.

				 * mac80211 queues our packets for us in this

				 * case, so this is really just a safety check.

				 */

				wiphy_warn(hw->wiphy,

					   "Cannot send packet while ADDBA "

					   "dialog is underway.\n");

				spin_unlock(&priv->stream_lock);

				dev_kfree_skb(skb);

				return;

			}

		} else {

			/* Defer calling mwl8k_start_stream so that the current

			 * skb can go out before the ADDBA request.  This

			 * prevents sequence number mismatch at the recepient

			 * as described above.

			 */

			stream = mwl8k_add_stream(hw, sta, tid);

			if (stream != NULL)

				start_ba_session = true;

		}

		spin_unlock(&priv->stream_lock);

	}



	dma = pci_map_single(priv->pdev, skb->data,

				skb->len, PCI_DMA_TODEVICE);



	if (pci_dma_mapping_error(priv->pdev, dma)) {

		wiphy_debug(hw->wiphy,

			    "failed to dma map skb, dropping TX frame.\n");

		if (start_ba_session) {

			spin_lock(&priv->stream_lock);

			mwl8k_remove_stream(hw, stream);

			spin_unlock(&priv->stream_lock);

		}

		dev_kfree_skb(skb);

		return;

	}
@@ -1740,12 +1805,22 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb) 


	txq = priv->txq + index;



	if (index >= MWL8K_TX_WMM_QUEUES && txq->len >= MWL8K_TX_DESCS) {

		/* This is the case in which the tx packet is destined for an

		 * AMPDU queue and that AMPDU queue is full.  Because we don't

		 * start and stop the AMPDU queues, we must drop these packets.

		 */

		dev_kfree_skb(skb);

		spin_unlock_bh(&priv->tx_lock);

		return;

	}



	BUG_ON(txq->skb[txq->tail] != NULL);

	txq->skb[txq->tail] = skb;



	tx = txq->txd + txq->tail;

	tx->data_rate = txdatarate;

	tx->tx_priority = index;

	tx->tx_priority = txpriority;

	tx->qos_control = cpu_to_le16(qos);

	tx->pkt_phys_addr = cpu_to_le32(dma);

	tx->pkt_len = cpu_to_le16(skb->len);
@@ -1764,12 +1839,20 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb) 
	if (txq->tail == MWL8K_TX_DESCS)

		txq->tail = 0;



	if (txq->head == txq->tail)

	if (txq->head == txq->tail && index < MWL8K_TX_WMM_QUEUES)

		ieee80211_stop_queue(hw, index);



	mwl8k_tx_start(priv);



	spin_unlock_bh(&priv->tx_lock);



	/* Initiate the ampdu session here */

	if (start_ba_session) {

		spin_lock(&priv->stream_lock);

		if (mwl8k_start_stream(hw, stream))

			mwl8k_remove_stream(hw, stream);

		spin_unlock(&priv->stream_lock);

	}

}
@@ -4632,21 +4715,118 @@ static int mwl8k_get_survey(struct ieee80211_hw *hw, int idx, 
	return 0;

}



#define MAX_AMPDU_ATTEMPTS 5



static int

mwl8k_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,

		   enum ieee80211_ampdu_mlme_action action,

		   struct ieee80211_sta *sta, u16 tid, u16 *ssn,

		   u8 buf_size)

{



	int i, rc = 0;

	struct mwl8k_priv *priv = hw->priv;

	struct mwl8k_ampdu_stream *stream;

	u8 *addr = sta->addr;



	if (!(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))

		return -ENOTSUPP;



	spin_lock(&priv->stream_lock);

	stream = mwl8k_lookup_stream(hw, addr, tid);



	switch (action) {

	case IEEE80211_AMPDU_RX_START:

	case IEEE80211_AMPDU_RX_STOP:

		if (!(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))

			return -ENOTSUPP;

		return 0;

		break;

	case IEEE80211_AMPDU_TX_START:

		/* By the time we get here the hw queues may contain outgoing

		 * packets for this RA/TID that are not part of this BA

		 * session.  The hw will assign sequence numbers to these

		 * packets as they go out.  So if we query the hw for its next

		 * sequence number and use that for the SSN here, it may end up

		 * being wrong, which will lead to sequence number mismatch at

		 * the recipient.  To avoid this, we reset the sequence number

		 * to O for the first MPDU in this BA stream.

		 */

		*ssn = 0;

		if (stream == NULL) {

			/* This means that somebody outside this driver called

			 * ieee80211_start_tx_ba_session.  This is unexpected

			 * because we do our own rate control.  Just warn and

			 * move on.

			 */

			wiphy_warn(hw->wiphy, "Unexpected call to %s.  "

				   "Proceeding anyway.\n", __func__);

			stream = mwl8k_add_stream(hw, sta, tid);

		}

		if (stream == NULL) {

			wiphy_debug(hw->wiphy, "no free AMPDU streams\n");

			rc = -EBUSY;

			break;

		}

		stream->state = AMPDU_STREAM_IN_PROGRESS;



		/* Release the lock before we do the time consuming stuff */

		spin_unlock(&priv->stream_lock);

		for (i = 0; i < MAX_AMPDU_ATTEMPTS; i++) {

			rc = mwl8k_check_ba(hw, stream);



			if (!rc)

				break;

			/*

			 * HW queues take time to be flushed, give them

			 * sufficient time

			 */



			msleep(1000);

		}

		spin_lock(&priv->stream_lock);

		if (rc) {

			wiphy_err(hw->wiphy, "Stream for tid %d busy after %d"

				" attempts\n", tid, MAX_AMPDU_ATTEMPTS);

			mwl8k_remove_stream(hw, stream);

			rc = -EBUSY;

			break;

		}

		ieee80211_start_tx_ba_cb_irqsafe(vif, addr, tid);

		break;

	case IEEE80211_AMPDU_TX_STOP:

		if (stream == NULL)

			break;

		if (stream->state == AMPDU_STREAM_ACTIVE) {

			spin_unlock(&priv->stream_lock);

			mwl8k_destroy_ba(hw, stream);

			spin_lock(&priv->stream_lock);

		}

		mwl8k_remove_stream(hw, stream);

		ieee80211_stop_tx_ba_cb_irqsafe(vif, addr, tid);

		break;

	case IEEE80211_AMPDU_TX_OPERATIONAL:

		BUG_ON(stream == NULL);

		BUG_ON(stream->state != AMPDU_STREAM_IN_PROGRESS);

		spin_unlock(&priv->stream_lock);

		rc = mwl8k_create_ba(hw, stream, buf_size);

		spin_lock(&priv->stream_lock);

		if (!rc)

			stream->state = AMPDU_STREAM_ACTIVE;

		else {

			spin_unlock(&priv->stream_lock);

			mwl8k_destroy_ba(hw, stream);

			spin_lock(&priv->stream_lock);

			wiphy_debug(hw->wiphy,

				"Failed adding stream for sta %pM tid %d\n",

				addr, tid);

			mwl8k_remove_stream(hw, stream);

		}

		break;



	default:

		return -ENOTSUPP;

		rc = -ENOTSUPP;

	}



	spin_unlock(&priv->stream_lock);

	return rc;

}



static const struct ieee80211_ops mwl8k_ops = {