From: Nishant Sarmukadam <nishants@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Pradeep Nemavat <pnemavat@xxxxxxxxxxx>
Brian Cavagnolo <brian@xxxxxxxxxxx>
Signed-off-by: Brian Cavagnolo <brian@xxxxxxxxxxx>
---
drivers/net/wireless/mwl8k.c | 194 ++++++++++++++++++++++++++++++++++++++++--
1 files changed, 187 insertions(+), 7 deletions(-)
diff --git a/drivers/net/wireless/mwl8k.c b/drivers/net/wireless/mwl8k.c
index dcd4508..ec1190a 100644
--- a/drivers/net/wireless/mwl8k.c
+++ b/drivers/net/wireless/mwl8k.c
@@ -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 = {
--
1.7.1.1
--
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
