1 files changed, 80 insertions, 43 deletions

diff --git a/drivers/net/bfin_mac.c b/drivers/net/bfin_mac.c
index 368f33313fb..012613fde3f 100644
--- a/drivers/net/bfin_mac.c
+++ b/drivers/net/bfin_mac.c
@@ -922,61 +922,73 @@ static void bfin_mac_hwtstamp_init(struct net_device *netdev)
 # define bfin_tx_hwtstamp(dev, skb)
 #endif
 
-static void adjust_tx_list(void)
+static inline void _tx_reclaim_skb(void)
+{
+        do {
+                tx_list_head->desc_a.config &= ~DMAEN;
+                tx_list_head->status.status_word = 0;
+                if (tx_list_head->skb) {
+                        dev_kfree_skb(tx_list_head->skb);
+                        tx_list_head->skb = NULL;
+                }
+                tx_list_head = tx_list_head->next;
+
+        } while (tx_list_head->status.status_word != 0);
+}
+
+static void tx_reclaim_skb(struct bfin_mac_local *lp)
 {
         int timeout_cnt = MAX_TIMEOUT_CNT;
 
-        if (tx_list_head->status.status_word != 0 &&
-            current_tx_ptr != tx_list_head) {
-                goto adjust_head;       /* released something, just return; */
-        }
+        if (tx_list_head->status.status_word != 0)
+                _tx_reclaim_skb();
 
-        /*
-         * if nothing released, check wait condition
-         * current's next can not be the head,
-         * otherwise the dma will not stop as we want
-         */
-        if (current_tx_ptr->next->next == tx_list_head) {
+        if (current_tx_ptr->next == tx_list_head) {
                 while (tx_list_head->status.status_word == 0) {
+                        /* slow down polling to avoid too many queue stop. */
                         udelay(10);
-                        if (tx_list_head->status.status_word != 0 ||
-                            !(bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)) {
-                                goto adjust_head;
-                        }
-                        if (timeout_cnt-- < 0) {
-                                printk(KERN_ERR DRV_NAME
-                                ": wait for adjust tx list head timeout\n");
+                        /* reclaim skb if DMA is not running. */
+                        if (!(bfin_read_DMA2_IRQ_STATUS() & DMA_RUN))
+                                break;
+                        if (timeout_cnt-- < 0)
                                 break;
-                        }
-                }
-                if (tx_list_head->status.status_word != 0) {
-                        goto adjust_head;
                 }
+
+                if (timeout_cnt >= 0)
+                        _tx_reclaim_skb();
+                else
+                        netif_stop_queue(lp->ndev);
         }
 
-        return;
+        if (current_tx_ptr->next != tx_list_head &&
+                netif_queue_stopped(lp->ndev))
+                netif_wake_queue(lp->ndev);
+
+        if (tx_list_head != current_tx_ptr) {
+                /* shorten the timer interval if tx queue is stopped */
+                if (netif_queue_stopped(lp->ndev))
+                        lp->tx_reclaim_timer.expires =
+                                jiffies + (TX_RECLAIM_JIFFIES >> 4);
+                else
+                        lp->tx_reclaim_timer.expires =
+                                jiffies + TX_RECLAIM_JIFFIES;
+
+                mod_timer(&lp->tx_reclaim_timer,
+                        lp->tx_reclaim_timer.expires);
+        }
 
-adjust_head:
-        do {
-                tx_list_head->desc_a.config &= ~DMAEN;
-                tx_list_head->status.status_word = 0;
-                if (tx_list_head->skb) {
-                        dev_kfree_skb(tx_list_head->skb);
-                        tx_list_head->skb = NULL;
-                } else {
-                        printk(KERN_ERR DRV_NAME
-                               ": no sk_buff in a transmitted frame!\n");
-                }
-                tx_list_head = tx_list_head->next;
-        } while (tx_list_head->status.status_word != 0 &&
-                 current_tx_ptr != tx_list_head);
         return;
+}
 
+static void tx_reclaim_skb_timeout(unsigned long lp)
+{
+        tx_reclaim_skb((struct bfin_mac_local *)lp);
 }
 
 static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
                                 struct net_device *dev)
 {
+        struct bfin_mac_local *lp = netdev_priv(dev);
         u16 *data;
         u32 data_align = (unsigned long)(skb->data) & 0x3;
         union skb_shared_tx *shtx = skb_tx(skb);
@@ -1009,8 +1021,6 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
                         skb->len);
                 current_tx_ptr->desc_a.start_addr =
                         (u32)current_tx_ptr->packet;
-                if (current_tx_ptr->status.status_word != 0)
-                        current_tx_ptr->status.status_word = 0;
                 blackfin_dcache_flush_range(
                         (u32)current_tx_ptr->packet,
                         (u32)(current_tx_ptr->packet + skb->len + 2));
@@ -1022,6 +1032,9 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
          */
         SSYNC();
 
+        /* always clear status buffer before start tx dma */
+        current_tx_ptr->status.status_word = 0;
+
         /* enable this packet's dma */
         current_tx_ptr->desc_a.config |= DMAEN;
 
@@ -1037,13 +1050,14 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
         bfin_write_EMAC_OPMODE(bfin_read_EMAC_OPMODE() | TE);
 
 out:
-        adjust_tx_list();
-
         bfin_tx_hwtstamp(dev, skb);
 
         current_tx_ptr = current_tx_ptr->next;
         dev->stats.tx_packets++;
         dev->stats.tx_bytes += (skb->len);
+
+        tx_reclaim_skb(lp);
+
         return NETDEV_TX_OK;
 }
 
@@ -1167,8 +1181,11 @@ real_rx:
 #ifdef CONFIG_NET_POLL_CONTROLLER
 static void bfin_mac_poll(struct net_device *dev)
 {
+        struct bfin_mac_local *lp = netdev_priv(dev);
+
         disable_irq(IRQ_MAC_RX);
         bfin_mac_interrupt(IRQ_MAC_RX, dev);
+        tx_reclaim_skb(lp);
         enable_irq(IRQ_MAC_RX);
 }
 #endif                          /* CONFIG_NET_POLL_CONTROLLER */
@@ -1232,12 +1249,27 @@ static int bfin_mac_enable(void)
 /* Our watchdog timed out. Called by the networking layer */
 static void bfin_mac_timeout(struct net_device *dev)
 {
+        struct bfin_mac_local *lp = netdev_priv(dev);
+
         pr_debug("%s: %s\n", dev->name, __func__);
 
         bfin_mac_disable();
 
-        /* reset tx queue */
-        tx_list_tail = tx_list_head->next;
+        del_timer(&lp->tx_reclaim_timer);
+
+        /* reset tx queue and free skb */
+        while (tx_list_head != current_tx_ptr) {
+                tx_list_head->desc_a.config &= ~DMAEN;
+                tx_list_head->status.status_word = 0;
+                if (tx_list_head->skb) {
+                        dev_kfree_skb(tx_list_head->skb);
+                        tx_list_head->skb = NULL;
+                }
+                tx_list_head = tx_list_head->next;
+        }
+
+        if (netif_queue_stopped(lp->ndev))
+                netif_wake_queue(lp->ndev);
 
         bfin_mac_enable();
 
@@ -1430,6 +1462,7 @@ static int __devinit bfin_mac_probe(struct platform_device *pdev)
         SET_NETDEV_DEV(ndev, &pdev->dev);
         platform_set_drvdata(pdev, ndev);
         lp = netdev_priv(ndev);
+        lp->ndev = ndev;
 
         /* Grab the MAC address in the MAC */
         *(__le32 *) (&(ndev->dev_addr[0])) = cpu_to_le32(bfin_read_EMAC_ADDRLO());
@@ -1485,6 +1518,10 @@ static int __devinit bfin_mac_probe(struct platform_device *pdev)
         ndev->netdev_ops = &bfin_mac_netdev_ops;
         ndev->ethtool_ops = &bfin_mac_ethtool_ops;
 
+        init_timer(&lp->tx_reclaim_timer);
+        lp->tx_reclaim_timer.data = (unsigned long)lp;
+        lp->tx_reclaim_timer.function = tx_reclaim_skb_timeout;
+
         spin_lock_init(&lp->lock);
 
         /* now, enable interrupts */