From 65f3ddcd08fe24490359274a8c9bf526e81357a5 Mon Sep 17 00:00:00 2001 From: Nishant Sarmukadam Date: Thu, 17 Mar 2011 11:58:46 -0700 Subject: [PATCH] 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 Pradeep Nemavat Brian Cavagnolo Signed-off-by: Brian Cavagnolo Signed-off-by: John W. Linville --- drivers/net/wireless/mwl8k.c | 194 +++++++++++++++++++++++++++++++++++++++++-- 1 file 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 = { -- 2.7.4