[PATCH 6/7] skge: compute available ring buffers

[Stephen Hemminger]

Don't need to keep track of available buffers, it is simpler
to just compute the value (ala e1000). Don't need tes on link up
because should always have available buffers then.

Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>


--- skge-2.6.orig/drivers/net/skge.c
+++ skge-2.6/drivers/net/skge.c
@@ -847,8 +847,7 @@ static void skge_link_up(struct skge_por
                    LED_BLK_OFF|LED_SYNC_OFF|LED_ON);
 
        netif_carrier_on(skge->netdev);
-       if (skge->tx_avail > MAX_SKB_FRAGS + 1)
-               netif_wake_queue(skge->netdev);
+       netif_wake_queue(skge->netdev);
 
        if (netif_msg_link(skge))
                printk(KERN_INFO PFX
@@ -2190,8 +2189,6 @@ static int skge_up(struct net_device *de
        if (err)
                goto free_rx_ring;
 
-       skge->tx_avail = skge->tx_ring.count - 1;
-
        /* Initialize MAC */
        spin_lock_bh(&hw->phy_lock);
        if (hw->chip_id == CHIP_ID_GENESIS)
@@ -2294,6 +2291,12 @@ static int skge_down(struct net_device *
        return 0;
 }
 
+static inline int skge_avail(const struct skge_ring *ring)
+{
+       return ((ring->to_clean > ring->to_use) ? 0 : ring->count)
+               + (ring->to_clean - ring->to_use) - 1;
+}
+
 static int skge_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 {
        struct skge_port *skge = netdev_priv(dev);
@@ -2314,7 +2317,7 @@ static int skge_xmit_frame(struct sk_buf
                return NETDEV_TX_LOCKED;
        }
 
-       if (unlikely(skge->tx_avail < skb_shinfo(skb)->nr_frags +1)) {
+       if (unlikely(skge_avail(&skge->tx_ring) < skb_shinfo(skb)->nr_frags + 
1)) {
                if (!netif_queue_stopped(dev)) {
                        netif_stop_queue(dev);
 
@@ -2390,8 +2393,7 @@ static int skge_xmit_frame(struct sk_buf
                       dev->name, e - ring->start, skb->len);
 
        ring->to_use = e->next;
-       skge->tx_avail -= skb_shinfo(skb)->nr_frags + 1;
-       if (skge->tx_avail <= MAX_SKB_FRAGS + 1) {
+       if (skge_avail(&skge->tx_ring) <= MAX_SKB_FRAGS + 1) {
                pr_debug("%s: transmit queue full\n", dev->name);
                netif_stop_queue(dev);
        }
@@ -2416,14 +2418,12 @@ static void skge_tx_complete(struct skge
                e->skb = NULL;
                pci_unmap_single(pdev, pci_unmap_addr(e, mapaddr),
                                 skb_headlen(skb), PCI_DMA_TODEVICE);
-               ++skge->tx_avail;
 
                for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
                        e = e->next;
                        pci_unmap_page(pdev, pci_unmap_addr(e, mapaddr),
                                       skb_shinfo(skb)->frags[i].size,
                                       PCI_DMA_TODEVICE);
-                       ++skge->tx_avail;
                }
 
                dev_kfree_skb(skb);
@@ -2688,7 +2688,7 @@ static void skge_tx_done(struct skge_por
 
        skge_write8(skge->hw, Q_ADDR(txqaddr[skge->port], Q_CSR), CSR_IRQ_CL_F);
 
-       if (skge->tx_avail > MAX_SKB_FRAGS + 1)
+       if (skge_avail(&skge->tx_ring) > MAX_SKB_FRAGS + 1)
                netif_wake_queue(skge->netdev);
 
        spin_unlock(&skge->tx_lock);
--- skge-2.6.orig/drivers/net/skge.h
+++ skge-2.6/drivers/net/skge.h
@@ -2418,7 +2418,6 @@ struct skge_port {
        int                  port;
 
        spinlock_t           tx_lock;
-       u32                  tx_avail;
        struct skge_ring     tx_ring;
        struct skge_ring     rx_ring;
 

--

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