mwl8k: mwl8k_txq_xmit() rework

Various mwl8k_txq_xmit changes:
- Extract the QoS field before adding the DMA header.
- Only write to tx->status once, and only after all the other
  descriptor fields have been set.
- Do all tx state manipulation under the tx spinlock.
- Remove the priv->inconfig check, as all transmit queues will
  be frozen during config cycles, so we won't ever be asked to
  transmit if a config cycle is running.
- Remove some more dead code.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 52 insertions, 93 deletions

diff --git a/drivers/net/wireless/mwl8k.c b/drivers/net/wireless/mwl8k.c
index 65eefe835024..88ba52e13af2 100644
--- a/drivers/net/wireless/mwl8k.c
+++ b/drivers/net/wireless/mwl8k.c
@@ -1257,46 +1257,60 @@ 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_hdr *wh;
         struct mwl8k_tx_queue *txq;
         struct mwl8k_tx_desc *tx;
-        struct mwl8k_dma_data *tr;
-        struct mwl8k_vif *mwl8k_vif;
         dma_addr_t dma;
-        u16 qos = 0;
-        bool qosframe = false, ampduframe = false;
-        bool mcframe = false, eapolframe = false;
-        bool amsduframe = false;
-        __le16 fc;
+        u32 txstatus;
+        u8 txdatarate;
+        u16 qos;
 
-        txq = priv->txq + index;
-        tx = txq->tx_desc_area + txq->tx_tail;
-
-        BUG_ON(txq->tx_skb[txq->tx_tail] != NULL);
+        wh = (struct ieee80211_hdr *)skb->data;
+        if (ieee80211_is_data_qos(wh->frame_control))
+                qos = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(wh)));
+        else
+                qos = 0;
 
-        /*
-         * Append HW DMA header to start of packet.
-         */
         mwl8k_add_dma_header(skb);
+        wh = &((struct mwl8k_dma_data *)skb->data)->wh;
 
         tx_info = IEEE80211_SKB_CB(skb);
         mwl8k_vif = MWL8K_VIF(tx_info->control.vif);
-        tr = (struct mwl8k_dma_data *)skb->data;
-        wh = &tr->wh;
-        fc = wh->frame_control;
-        qosframe = ieee80211_is_data_qos(fc);
-        mcframe = is_multicast_ether_addr(wh->addr1);
-        ampduframe = !!(tx_info->flags & IEEE80211_TX_CTL_AMPDU);
 
         if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
                 u16 seqno = mwl8k_vif->seqno;
+
                 wh->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
                 wh->seq_ctrl |= cpu_to_le16(seqno << 4);
                 mwl8k_vif->seqno = seqno++ % 4096;
         }
 
-        if (qosframe)
-                qos = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(wh)));
+        /* Setup firmware control bit fields for each frame type.  */
+        txstatus = 0;
+        txdatarate = 0;
+        if (ieee80211_is_mgmt(wh->frame_control) ||
+            ieee80211_is_ctl(wh->frame_control)) {
+                txdatarate = 0;
+                qos = mwl8k_qos_setbit_eosp(qos);
+                /* Set Queue size to unspecified */
+                qos = mwl8k_qos_setbit_qlen(qos, 0xff);
+        } else if (ieee80211_is_data(wh->frame_control)) {
+                txdatarate = 1;
+                if (is_multicast_ether_addr(wh->addr1))
+                        txstatus |= MWL8K_TXD_STATUS_MULTICAST_TX;
+
+                /* Send pkt in an aggregate if AMPDU frame.  */
+                if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
+                        qos = mwl8k_qos_setbit_ack(qos,
+                                MWL8K_TXD_ACK_POLICY_BLOCKACK);
+                else
+                        qos = mwl8k_qos_setbit_ack(qos,
+                                MWL8K_TXD_ACK_POLICY_NORMAL);
+
+                if (qos & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
+                        qos = mwl8k_qos_setbit_amsdu(qos);
+        }
 
         dma = pci_map_single(priv->pdev, skb->data,
                                 skb->len, PCI_DMA_TODEVICE);
@@ -1304,95 +1318,40 @@ mwl8k_txq_xmit(struct ieee80211_hw *hw, int index, struct sk_buff *skb)
         if (pci_dma_mapping_error(priv->pdev, dma)) {
                 printk(KERN_DEBUG "%s: failed to dma map skb, "
                         "dropping TX frame.\n", priv->name);
-
-                if (skb != NULL)
-                        dev_kfree_skb(skb);
+                dev_kfree_skb(skb);
                 return NETDEV_TX_OK;
         }
 
-        /* Set desc header, cpu bit order.  */
-        tx->status = 0;
-        tx->data_rate = 0;
-        tx->tx_priority = index;
-        tx->qos_control = 0;
-        tx->rate_info = 0;
-        tx->peer_id = mwl8k_vif->peer_id;
-
-        amsduframe = !!(qos & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT);
-
-        /* Setup firmware control bit fields for each frame type.  */
-        if (ieee80211_is_mgmt(fc) || ieee80211_is_ctl(fc)) {
-                tx->data_rate = 0;
-                qos = mwl8k_qos_setbit_eosp(qos);
-                /* Set Queue size to unspecified */
-                qos = mwl8k_qos_setbit_qlen(qos, 0xff);
-        } else if (ieee80211_is_data(fc)) {
-                tx->data_rate = 1;
-                if (mcframe)
-                        tx->status |= MWL8K_TXD_STATUS_MULTICAST_TX;
+        spin_lock_bh(&priv->tx_lock);
 
-                /*
-                 * Tell firmware to not send EAPOL pkts in an
-                 * aggregate.  Verify against mac80211 tx path.  If
-                 * stack turns off AMPDU for an EAPOL frame this
-                 * check will be removed.
-                 */
-                if (eapolframe) {
-                        qos = mwl8k_qos_setbit_ack(qos,
-                                MWL8K_TXD_ACK_POLICY_NORMAL);
-                } else {
-                        /* Send pkt in an aggregate if AMPDU frame.  */
-                        if (ampduframe)
-                                qos = mwl8k_qos_setbit_ack(qos,
-                                        MWL8K_TXD_ACK_POLICY_BLOCKACK);
-                        else
-                                qos = mwl8k_qos_setbit_ack(qos,
-                                        MWL8K_TXD_ACK_POLICY_NORMAL);
+        txq = priv->txq + index;
 
-                        if (amsduframe)
-                                qos = mwl8k_qos_setbit_amsdu(qos);
-                }
-        }
+        BUG_ON(txq->tx_skb[txq->tx_tail] != NULL);
+        txq->tx_skb[txq->tx_tail] = skb;
 
-        /* Convert to little endian */
+        tx = txq->tx_desc_area + txq->tx_tail;
+        tx->data_rate = txdatarate;
+        tx->tx_priority = index;
         tx->qos_control = cpu_to_le16(qos);
-        tx->status = cpu_to_le32(tx->status);
         tx->pkt_phys_addr = cpu_to_le32(dma);
         tx->pkt_len = cpu_to_le16(skb->len);
-
-        txq->tx_skb[txq->tx_tail] = skb;
-
-        spin_lock_bh(&priv->tx_lock);
-
-        tx->status = cpu_to_le32(MWL8K_TXD_STATUS_OK |
-                                        MWL8K_TXD_STATUS_FW_OWNED);
+        tx->rate_info = 0;
+        tx->peer_id = mwl8k_vif->peer_id;
         wmb();
+        tx->status = cpu_to_le32(MWL8K_TXD_STATUS_FW_OWNED | txstatus);
+
+        txq->tx_stats.count++;
         txq->tx_stats.len++;
         priv->pending_tx_pkts++;
-        txq->tx_stats.count++;
-        txq->tx_tail++;
 
+        txq->tx_tail++;
         if (txq->tx_tail == MWL8K_TX_DESCS)
                 txq->tx_tail = 0;
+
         if (txq->tx_head == txq->tx_tail)
                 ieee80211_stop_queue(hw, index);
 
-        if (priv->inconfig) {
-                /*
-                 * Silently queue packet when we are in the middle of
-                 * a config cycle.  Notify firmware only if we are
-                 * waiting for TXQs to empty.  If a packet is sent
-                 * before .config() is complete, perhaps it is better
-                 * to drop the packet, as the channel is being changed
-                 * and the packet will end up on the wrong channel.
-                 */
-                printk(KERN_ERR "%s(): WARNING TX activity while "
-                        "in config\n", __func__);
-
-                if (priv->tx_wait != NULL)
-                        mwl8k_tx_start(priv);
-        } else
-                mwl8k_tx_start(priv);
+        mwl8k_tx_start(priv);
 
         spin_unlock_bh(&priv->tx_lock);