libertas: clean up lbs_hard_start_xmit()

Having merged the nest of functions into one, now we can clean it up and
fix the error handling, and the duplication -- and at least make a start
on the locking.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/libertas/tx.c b/drivers/net/wireless/libertas/tx.c
index 7bc2124..aefe524 100644 (file)
--- a/drivers/net/wireless/libertas/tx.c
+++ b/drivers/net/wireless/libertas/tx.c
@@ -58,22 +58,16 @@ static u32 convert_radiotap_rate_to_mv(u8 rate)
  */
 int lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
+       unsigned long flags;
        struct lbs_private *priv = dev->priv;
-       int ret = -1;
-       struct txpd localtxpd;
-       struct txpd *plocaltxpd = &localtxpd;
-       u8 *p802x_hdr;
-       struct tx_radiotap_hdr *pradiotap_hdr;
-       u32 new_rate;
-       u8 *ptr = priv->tmptxbuf;
+       struct txpd *txpd;
+       char *p802x_hdr;
+       uint16_t pkt_len;
+       int ret;
 
        lbs_deb_enter(LBS_DEB_TX);
 
-       lbs_deb_hex(LBS_DEB_TX, "TX Data", skb->data, min_t(unsigned int, skb->len, 100));
-
-       netif_stop_queue(priv->dev);
-       if (priv->mesh_dev)
-               netif_stop_queue(priv->mesh_dev);
+       ret = NETDEV_TX_BUSY;
 
        if (priv->dnld_sent) {
                lbs_pr_alert( "TX error: dnld_sent = %d, not sending\n",
@@ -94,98 +88,97 @@ int lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
        }
 
        if (priv->surpriseremoved)
-               return -1;
+               goto drop;
 
        if (!skb->len || (skb->len > MRVDRV_ETH_TX_PACKET_BUFFER_SIZE)) {
                lbs_deb_tx("tx err: skb length %d 0 or > %zd\n",
                       skb->len, MRVDRV_ETH_TX_PACKET_BUFFER_SIZE);
-               goto done_tx;
+               /* We'll never manage to send this one; drop it and return 'OK' */
+               goto drop;
        }
 
-       ret = 0;
-       memset(plocaltxpd, 0, sizeof(struct txpd));
-
-       plocaltxpd->tx_packet_length = cpu_to_le16(skb->len);
+       lbs_deb_hex(LBS_DEB_TX, "TX Data", skb->data, min_t(unsigned int, skb->len, 100));
 
-       /* offset of actual data */
-       plocaltxpd->tx_packet_location = cpu_to_le32(sizeof(struct txpd));
+       txpd = (void *)priv->tmptxbuf;
+       memset(txpd, 0, sizeof(struct txpd));
 
        p802x_hdr = skb->data;
-       if (priv->monitormode != LBS_MONITOR_OFF) {
+       pkt_len = skb->len;
 
-               /* locate radiotap header */
-               pradiotap_hdr = (struct tx_radiotap_hdr *)skb->data;
+       if (priv->monitormode != LBS_MONITOR_OFF) {
+               struct tx_radiotap_hdr *rtap_hdr = (void *)skb->data;
 
                /* set txpd fields from the radiotap header */
-               new_rate = convert_radiotap_rate_to_mv(pradiotap_hdr->rate);
-               if (new_rate != 0) {
-                       /* use new tx_control[4:0] */
-                       plocaltxpd->tx_control = cpu_to_le32(new_rate);
-               }
+               txpd->tx_control = cpu_to_le32(convert_radiotap_rate_to_mv(rtap_hdr->rate));
 
                /* skip the radiotap header */
-               p802x_hdr += sizeof(struct tx_radiotap_hdr);
-               plocaltxpd->tx_packet_length =
-                       cpu_to_le16(le16_to_cpu(plocaltxpd->tx_packet_length)
-                                   - sizeof(struct tx_radiotap_hdr));
+               p802x_hdr += sizeof(*rtap_hdr);
+               pkt_len -= sizeof(*rtap_hdr);
 
+               /* copy destination address from 802.11 header */
+               memcpy(txpd->tx_dest_addr_high, p802x_hdr + 4, ETH_ALEN);
+       } else {
+               /* copy destination address from 802.3 header */
+               memcpy(txpd->tx_dest_addr_high, p802x_hdr, ETH_ALEN);
        }
-       /* copy destination address from 802.3 or 802.11 header */
-       if (priv->monitormode != LBS_MONITOR_OFF)
-               memcpy(plocaltxpd->tx_dest_addr_high, p802x_hdr + 4, ETH_ALEN);
-       else
-               memcpy(plocaltxpd->tx_dest_addr_high, p802x_hdr, ETH_ALEN);
 
-       lbs_deb_hex(LBS_DEB_TX, "txpd", (u8 *) plocaltxpd, sizeof(struct txpd));
+       txpd->tx_packet_length = cpu_to_le16(pkt_len);
+       txpd->tx_packet_location = cpu_to_le32(sizeof(struct txpd));
 
-       if (IS_MESH_FRAME(skb)) {
-               plocaltxpd->tx_control |= cpu_to_le32(TxPD_MESH_FRAME);
-       }
+       if (dev == priv->mesh_dev)
+               txpd->tx_control |= cpu_to_le32(TxPD_MESH_FRAME);
 
-       memcpy(ptr, plocaltxpd, sizeof(struct txpd));
+       lbs_deb_hex(LBS_DEB_TX, "txpd", (u8 *) &txpd, sizeof(struct txpd));
 
-       ptr += sizeof(struct txpd);
+       lbs_deb_hex(LBS_DEB_TX, "Tx Data", (u8 *) p802x_hdr, le16_to_cpu(txpd->tx_packet_length));
 
-       lbs_deb_hex(LBS_DEB_TX, "Tx Data", (u8 *) p802x_hdr, le16_to_cpu(plocaltxpd->tx_packet_length));
-       memcpy(ptr, p802x_hdr, le16_to_cpu(plocaltxpd->tx_packet_length));
-       ret = priv->hw_host_to_card(priv, MVMS_DAT,
-                                   priv->tmptxbuf,
-                                   le16_to_cpu(plocaltxpd->tx_packet_length) +
-                                   sizeof(struct txpd));
+       memcpy(&txpd[1], p802x_hdr, le16_to_cpu(txpd->tx_packet_length));
 
-       if (ret) {
-               lbs_deb_tx("tx err: hw_host_to_card returned 0x%X\n", ret);
-               goto done_tx;
-       }
+       /* We need to protect against the queues being restarted before
+          we get round to stopping them */
+       spin_lock_irqsave(&priv->driver_lock, flags);
 
-       lbs_deb_tx("%s succeeds\n", __func__);
+       ret = priv->hw_host_to_card(priv, MVMS_DAT, priv->tmptxbuf,
+                                   pkt_len + sizeof(struct txpd));
 
-done_tx:
        if (!ret) {
+               lbs_deb_tx("%s succeeds\n", __func__);
+
+               /* Stop processing outgoing pkts before submitting */
+               netif_stop_queue(priv->dev);
+               if (priv->mesh_dev)
+                       netif_stop_queue(priv->mesh_dev);
+
                priv->stats.tx_packets++;
                priv->stats.tx_bytes += skb->len;
 
-               dev->trans_start = jiffies;
-       } else {
-               priv->stats.tx_dropped++;
-               priv->stats.tx_errors++;
+               dev->trans_start = jiffies;
+
+               if (priv->monitormode != LBS_MONITOR_OFF) {
+                       /* Keep the skb to echo it back once Tx feedback is
+                          received from FW */
+                       skb_orphan(skb);
+
+                       /* Keep the skb around for when we get feedback */
+                       priv->currenttxskb = skb;
+               }
        }
+       
+       spin_unlock_irqrestore(&priv->driver_lock, flags);
 
-       if (!ret && priv->monitormode != LBS_MONITOR_OFF) {
-               /* Keep the skb to echo it back once Tx feedback is
-                  received from FW */
-               skb_orphan(skb);
-               /* stop processing outgoing pkts */
-               netif_stop_queue(priv->dev);
-               if (priv->mesh_dev)
-                       netif_stop_queue(priv->mesh_dev);
+       if (ret) {
+               lbs_deb_tx("tx err: hw_host_to_card returned 0x%X\n", ret);
+drop:
+               priv->stats.tx_dropped++;
+               priv->stats.tx_errors++;
 
-               /* Keep the skb around for when we get feedback */
-               priv->currenttxskb = skb;
-       } else {
                dev_kfree_skb_any(skb);
        }
 
+       /* Even if we dropped the packet, return OK. Otherwise the
+          packet gets requeued. */
+       ret = NETDEV_TX_OK;
+
 done:
        lbs_deb_leave_args(LBS_DEB_TX, "ret %d", ret);
        return ret;