libertas: Move actual transmission to main thread

The locking issues with TX, especially TX from multiple netdevs, get
_so_ much easier if you do it like this.

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

diff --git a/drivers/net/wireless/libertas/dev.h b/drivers/net/wireless/libertas/dev.h
index 04cf33d..4681405 100644 (file)
--- a/drivers/net/wireless/libertas/dev.h
+++ b/drivers/net/wireless/libertas/dev.h
@@ -164,7 +164,10 @@ struct lbs_private {
 
        struct mutex lock;
 
-       u8 tmptxbuf[LBS_UPLD_SIZE];
+       /* TX packet ready to be sent... */
+       int tx_pending_len;             /* -1 while building packet */
+
+       u8 tx_pending_buf[LBS_UPLD_SIZE];
        /* protected by hard_start_xmit serialization */
 
        /** command-related variables */

diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
index 42b64b5..f16c93b 100644 (file)
--- a/drivers/net/wireless/libertas/main.c
+++ b/drivers/net/wireless/libertas/main.c
@@ -739,6 +739,8 @@ static int lbs_thread(void *data)
                        shouldsleep = 0;        /* Interrupt pending. Deal with it now */
                else if (priv->dnld_sent)
                        shouldsleep = 1;        /* Something is en route to the device already */
+               else if (priv->tx_pending_len > 0)
+                       shouldsleep = 0;        /* We've a packet to send */
                else if (priv->cur_cmd)
                        shouldsleep = 1;        /* Can't send a command; one already running */
                else if (!list_empty(&priv->cmdpendingq))
@@ -852,6 +854,28 @@ static int lbs_thread(void *data)
                 */
                if (!list_empty(&priv->cmdpendingq))
                        wake_up_all(&priv->cmd_pending);
+
+               spin_lock_irq(&priv->driver_lock);
+               if (!priv->dnld_sent && priv->tx_pending_len > 0) {
+                       int ret = priv->hw_host_to_card(priv, MVMS_DAT,
+                                                       priv->tx_pending_buf,
+                                                       priv->tx_pending_len);
+                       if (ret) {
+                               lbs_deb_tx("host_to_card failed %d\n", ret);
+                               priv->dnld_sent = DNLD_RES_RECEIVED;
+                       }
+                       priv->tx_pending_len = 0;
+                       if (!priv->currenttxskb) {
+                               /* We can wake the queues immediately if we aren't
+                                  waiting for TX feedback */
+                               if (priv->connect_status == LBS_CONNECTED)
+                                       netif_wake_queue(priv->dev);
+                               if (priv->mesh_dev &&
+                                   priv->mesh_connect_status == LBS_CONNECTED)
+                                       netif_wake_queue(priv->mesh_dev);
+                       }
+               }
+               spin_unlock_irq(&priv->driver_lock);
        }
 
        del_timer(&priv->command_timer);

diff --git a/drivers/net/wireless/libertas/tx.c b/drivers/net/wireless/libertas/tx.c
index 300aa05..e2141f0 100644 (file)
--- a/drivers/net/wireless/libertas/tx.c
+++ b/drivers/net/wireless/libertas/tx.c
@@ -67,39 +67,45 @@ int lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        lbs_deb_enter(LBS_DEB_TX);
 
-       ret = NETDEV_TX_BUSY;
-
-       if (priv->dnld_sent) {
-               lbs_pr_alert( "TX error: dnld_sent = %d, not sending\n",
-                      priv->dnld_sent);
-               goto done;
-       }
-
-       if (priv->currenttxskb) {
-               lbs_pr_err("%s while TX skb pending\n", __func__);
-               goto done;
-       }
+       ret = NETDEV_TX_OK;
 
-       if ((priv->psstate == PS_STATE_SLEEP) ||
-           (priv->psstate == PS_STATE_PRE_SLEEP)) {
-               lbs_pr_alert("TX error: packet xmit in %ssleep mode\n",
-                            priv->psstate == PS_STATE_SLEEP?"":"pre-");
-               goto done;
-       }
+       /* We need to protect against the queues being restarted before
+          we get round to stopping them */
+       spin_lock_irqsave(&priv->driver_lock, flags);
 
        if (priv->surpriseremoved)
-               goto drop;
+               goto free;
 
        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);
                /* We'll never manage to send this one; drop it and return 'OK' */
-               goto drop;
+
+               priv->stats.tx_dropped++;
+               priv->stats.tx_errors++;
+               goto free;
+       }
+
+
+       netif_stop_queue(priv->dev);
+       if (priv->mesh_dev)
+               netif_stop_queue(priv->mesh_dev);
+
+       if (priv->tx_pending_len) {
+               /* This can happen if packets come in on the mesh and eth 
+                  device simultaneously -- there's no mutual exclusion on 
+                  hard_start_xmit() calls between devices. */
+               lbs_deb_tx("Packet on %s while busy\n", dev->name);
+               ret = NETDEV_TX_BUSY;
+               goto unlock;
        }
 
+       priv->tx_pending_len = -1;
+       spin_unlock_irqrestore(&priv->driver_lock, flags);
+
        lbs_deb_hex(LBS_DEB_TX, "TX Data", skb->data, min_t(unsigned int, skb->len, 100));
 
-       txpd = (void *)priv->tmptxbuf;
+       txpd = (void *)priv->tx_pending_buf;
        memset(txpd, 0, sizeof(struct txpd));
 
        p802x_hdr = skb->data;
@@ -134,54 +140,31 @@ int lbs_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        memcpy(&txpd[1], p802x_hdr, le16_to_cpu(txpd->tx_packet_length));
 
-       /* We need to protect against the queues being restarted before
-          we get round to stopping them */
        spin_lock_irqsave(&priv->driver_lock, flags);
+       priv->tx_pending_len = pkt_len + sizeof(struct txpd);
 
-       ret = priv->hw_host_to_card(priv, MVMS_DAT, priv->tmptxbuf,
-                                   pkt_len + sizeof(struct txpd));
-
-       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;
+       lbs_deb_tx("%s lined up packet\n", __func__);
 
-               if (priv->monitormode != LBS_MONITOR_OFF) {
-                       /* Keep the skb to echo it back once Tx feedback is
-                          received from FW */
-                       skb_orphan(skb);
+       priv->stats.tx_packets++;
+       priv->stats.tx_bytes += skb->len;
 
-                       /* Keep the skb around for when we get feedback */
-                       priv->currenttxskb = skb;
-               } else
-                       dev_kfree_skb_any(skb);
-               
-       }
-       
-       spin_unlock_irqrestore(&priv->driver_lock, flags);
+       dev->trans_start = jiffies;
 
-       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++;
+       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;
+       } else {
+ free:
                dev_kfree_skb_any(skb);
        }
+ unlock:
+       spin_unlock_irqrestore(&priv->driver_lock, flags);
+       wake_up(&priv->waitq);
 
-       /* 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;
 }