ar7: cpmac: use fixed-size ringbuffers for rx/tx descriptors, use single
authorEugene Konev <ejka@imfi.kspu.ru>
Tue, 27 Mar 2007 15:19:08 +0000 (15:19 +0000)
committerEugene Konev <ejka@imfi.kspu.ru>
Tue, 27 Mar 2007 15:19:08 +0000 (15:19 +0000)
channel rx, move skb allocation out of interrupt, general cleanup

SVN-Revision: 6724

target/linux/ar7-2.6/files/drivers/net/cpmac.c

index 3c4c1b2..9847a41 100644 (file)
@@ -28,6 +28,7 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/delay.h>
+#include <linux/version.h>
 
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
@@ -194,23 +195,29 @@ struct cpmac_desc {
 struct cpmac_priv {
        struct net_device_stats stats;
        spinlock_t lock;
-       int free_tx_channels;
-       struct cpmac_desc *tx_pool;
-       struct cpmac_desc *rx_channels[8];
-       struct cpmac_desc *tx_channels[8];
+       struct sk_buff *skb_pool;
+       int free_skbs;
+       struct cpmac_desc *rx_head;
+       int tx_head, tx_tail;
+       struct cpmac_desc *desc_ring;
        struct cpmac_regs *regs;
        struct mii_bus *mii_bus;
        struct phy_device *phy;
        char phy_name[BUS_ID_SIZE];
-       unsigned long pages;
-       int order;
        struct plat_cpmac_data *config;
        int oldlink, oldspeed, oldduplex;
        u32 msg_enable;
+       struct net_device *dev;
+       struct work_struct alloc_work;
 };
 
 static irqreturn_t cpmac_irq(int, void *);
-void cpmac_exit(void);
+
+#define CPMAC_LOW_THRESH 8
+#define CPMAC_ALLOC_SIZE 32
+#define CPMAC_SKB_SIZE 1536
+#define CPMAC_TX_RING_SIZE 8
+#define CPMAC_RX_RING_SIZE 16
 
 #ifdef CPMAC_DEBUG
 static void cpmac_dump_regs(u32 *base, int count)
@@ -263,7 +270,7 @@ static int cpmac_mdio_reset(struct mii_bus *bus)
 
 static int mii_irqs[PHY_MAX_ADDR] = { PHY_POLL, };
 
-struct mii_bus cpmac_mii = {
+static struct mii_bus cpmac_mii = {
        .name = "cpmac-mii",
        .read = cpmac_mdio_read,
        .write = cpmac_mdio_write,
@@ -271,7 +278,7 @@ struct mii_bus cpmac_mii = {
        .irq = mii_irqs,
 };
 
-int cpmac_config(struct net_device *dev, struct ifmap *map)
+static int cpmac_config(struct net_device *dev, struct ifmap *map)
 {
        if (dev->flags & IFF_UP)
                return -EBUSY;
@@ -284,7 +291,7 @@ int cpmac_config(struct net_device *dev, struct ifmap *map)
        return 0;
 }
 
-int cpmac_set_mac_address(struct net_device *dev, void *addr)
+static int cpmac_set_mac_address(struct net_device *dev, void *addr)
 {
        struct sockaddr *sa = addr;
 
@@ -296,7 +303,7 @@ int cpmac_set_mac_address(struct net_device *dev, void *addr)
        return 0;
 }
 
-void cpmac_set_multicast_list(struct net_device *dev)
+static void cpmac_set_multicast_list(struct net_device *dev)
 {
        struct dev_mc_list *iter;
        int i;
@@ -343,95 +350,132 @@ void cpmac_set_multicast_list(struct net_device *dev)
        }
 }
 
-static void cpmac_rx(struct net_device *dev, int channel)
+static struct sk_buff *cpmac_get_skb(struct net_device *dev) 
 {
-       struct cpmac_desc *pkt;
        struct sk_buff *skb;
+       struct cpmac_priv *priv = netdev_priv(dev);
+
+       skb = priv->skb_pool;
+       if (likely(skb))
+               priv->skb_pool = skb->next;
+
+       if (likely(priv->free_skbs))
+               priv->free_skbs--;
+
+       if (priv->free_skbs < CPMAC_LOW_THRESH)
+               schedule_work(&priv->alloc_work);
+
+       return skb;
+}
+
+static void cpmac_rx(struct net_device *dev, int channel)
+{
        char *data;
+       struct sk_buff *skb;
+       struct cpmac_desc *desc;
        struct cpmac_priv *priv = netdev_priv(dev);
 
        spin_lock(&priv->lock);
-       pkt = priv->rx_channels[channel];
-       if (!pkt) {
-               if (printk_ratelimit())
-                       printk(KERN_NOTICE "%s: rx: spurious interrupt\n",
-                              dev->name); 
-               priv->stats.rx_errors++;
+       if (unlikely(!priv->rx_head))
                return;
-       }
 
-       priv->regs->rx_ack[channel] = virt_to_phys(pkt);
-       dma_cache_inv((u32)pkt, 16);
-       if (!pkt->datalen) {
-               if (printk_ratelimit())
-                       printk(KERN_NOTICE "%s: rx: spurious interrupt\n",
-                              dev->name); 
-               priv->stats.rx_errors++;
-               return;
-       }
-       skb = dev_alloc_skb(1536);
-       if (!skb) {
-               if (printk_ratelimit())
-                       printk(KERN_NOTICE "%s: rx: low on mem - packet dropped\n",
-                              dev->name); 
-               priv->stats.rx_dropped++;
-       } else {
-               data = (char *)phys_to_virt(pkt->hw_data);
-               dma_cache_inv((u32)data, pkt->datalen);
-               skb_put(pkt->skb, pkt->datalen);
-               pkt->skb->protocol = eth_type_trans(pkt->skb, dev);
-               pkt->skb->ip_summed = CHECKSUM_NONE;
-               priv->stats.rx_packets++;
-               priv->stats.rx_bytes += pkt->datalen;
-               netif_rx(pkt->skb);
-               skb_reserve(skb, 2);
-               skb->dev = dev;
-               pkt->skb = skb;
-               pkt->hw_data = virt_to_phys(skb->data);
+       desc = priv->rx_head;
+       dma_cache_inv((u32)desc, 16);
+
+       while((desc->dataflags & CPMAC_OWN) == 0) {
+               priv->regs->rx_ack[0] = virt_to_phys(desc);
+               if (unlikely(!desc->datalen)) {
+                       if (printk_ratelimit())
+                               printk(KERN_NOTICE "%s: rx: spurious interrupt\n",
+                                      dev->name);
+                       priv->stats.rx_errors++;
+                       goto out;
+               }
+
+               skb = cpmac_get_skb(dev);
+               if (likely(skb)) {
+                       data = (char *)phys_to_virt(desc->hw_data);
+                       dma_cache_inv((u32)data, desc->datalen);
+                       skb_put(desc->skb, desc->datalen);
+                       desc->skb->protocol = eth_type_trans(desc->skb, dev);
+                       desc->skb->ip_summed = CHECKSUM_NONE;
+                       priv->stats.rx_packets++;
+                       priv->stats.rx_bytes += desc->datalen;
+                       netif_rx(desc->skb);
+                       desc->skb = skb;
+               } else {
+                       if (printk_ratelimit())
+                               printk(KERN_NOTICE "%s: rx: no free skbs, dropping packet\n",
+                                      dev->name);
+                       priv->stats.rx_dropped++;
+               }
+               desc->hw_data = virt_to_phys(desc->skb->data);
+               desc->buflen = CPMAC_SKB_SIZE;
+               desc->dataflags = CPMAC_OWN;
+               dma_cache_wback((u32)desc, 16);
+               desc = desc->next;
+               dma_cache_inv((u32)desc, 16);
        }
+out:
+       priv->rx_head = desc;
        spin_unlock(&priv->lock);
-       pkt->buflen = 1500 + ETH_HLEN + 4;
-       pkt->datalen = 0;
-       pkt->dataflags = CPMAC_OWN;
-       dma_cache_wback_inv((u32)pkt, 16);
-       priv->regs->rx_ptr[channel] = virt_to_phys(pkt);
+       priv->regs->rx_ptr[0] = virt_to_phys(priv->rx_head);
 }
 
-struct cpmac_desc *cpmac_get_desc(struct net_device *dev) 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
+static void
+cpmac_alloc_skbs(struct work_struct *work)
 {
-       struct cpmac_desc *pkt;
-       struct cpmac_priv *priv = netdev_priv(dev);
-       pkt = priv->tx_pool;
-       priv->tx_pool = pkt->next;
-       pkt->next = NULL;
-       if (priv->tx_pool == NULL)
-               netif_stop_queue(dev);
-       return pkt;
-}
-
-void cpmac_release_desc(struct net_device *dev, struct cpmac_desc *pkt)
+        struct cpmac_priv *priv = container_of(work, struct cpmac_priv,
+                                              alloc_work);
+#else
+static void
+cpmac_alloc_skbs(void *data)
 {
+        struct net_device *dev = (struct net_device*)data;
        struct cpmac_priv *priv = netdev_priv(dev);
-       struct cpmac_desc *p;
-       p = pkt;
-       while (p->next) p = p->next;
-       p->next = priv->tx_pool;
-       priv->tx_pool = pkt;
+#endif
+       unsigned long flags;
+       int i, num_skbs = 0;
+       struct sk_buff *skb, *skbs = NULL;
+
+       for (i = 0; i < CPMAC_ALLOC_SIZE; i++) {
+               skb = alloc_skb(CPMAC_SKB_SIZE + 2, GFP_KERNEL);
+               if (!skb)
+                       break;
+               skb->next = skbs;
+               skb_reserve(skb, 2);
+               skb->dev = priv->dev;
+               num_skbs++;
+               skbs = skb;
+       }
+
+       if (skbs) {
+               spin_lock_irqsave(&priv->lock, flags);
+               for (skb = priv->skb_pool; skb && skb->next; skb = skb->next);
+               if (!skb) {
+                       priv->skb_pool = skbs;
+               } else {
+                       skb->next = skbs;
+               }
+               priv->free_skbs += num_skbs;
+               spin_unlock_irqrestore(&priv->lock, flags);
+#ifdef CPMAC_DEBUG
+               printk("%s: allocated %d skbs\n", priv->dev->name, num_skbs);
+#endif
+       }
 }
 
-int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        unsigned long flags;
-       int i, len, frag;
-       skb_frag_t *this_frag;
-       void *data;
-       struct cpmac_desc *head, *tail, *curr;
+       int len, chan;
+       struct cpmac_desc *desc;
        struct cpmac_priv *priv = netdev_priv(dev);
 
-       BUG_ON(priv->free_tx_channels < 1);
        len = skb->len;
-       if (len < ETH_ZLEN) {
-               if (skb_padto(skb, ETH_ZLEN)) {
+       if (unlikely(len < ETH_ZLEN)) {
+               if (unlikely(skb_padto(skb, ETH_ZLEN))) {
                        if (printk_ratelimit())
                                printk(KERN_NOTICE "%s: padding failed, dropping\n",
                                       dev->name); 
@@ -443,66 +487,51 @@ int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev)
                len = ETH_ZLEN;
        }
        spin_lock_irqsave(&priv->lock, flags);
-       dev->trans_start = jiffies;
-       for (i = 0; i < 8; i++)
-               if (!priv->tx_channels[i])
-                       break;
-
-       BUG_ON(i == 8);
-
-       head = cpmac_get_desc(dev);
-       priv->tx_channels[i] = head;
-       head->jiffies = dev->trans_start;
-       if (!(--priv->free_tx_channels))
+       chan = priv->tx_tail++;
+       priv->tx_tail %= 8;
+       if (priv->tx_tail == priv->tx_head)
                netif_stop_queue(dev);
+
+       desc = &priv->desc_ring[chan];
+       dev->trans_start = jiffies;
+       desc->jiffies = dev->trans_start;
        spin_unlock_irqrestore(&priv->lock, flags);
 
-       head->dataflags = CPMAC_SOP | CPMAC_OWN;
-       head->skb = skb;
-       head->hw_data = virt_to_phys(skb->data);
-       dma_cache_wback_inv((u32)skb->data, len);
-       head->buflen = len;
-       head->datalen = len;
-       tail = head;
-       for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
-               dma_cache_wback_inv((u32)tail, 16);
-               this_frag = &skb_shinfo(skb)->frags[frag];
-               curr = cpmac_get_desc(dev);
-               data = page_address(this_frag->page) +
-                       this_frag->page_offset;
-               curr->hw_data = virt_to_phys(data);
-               curr->buflen = this_frag->size;
-               curr->datalen = this_frag->size;
-               curr->dataflags = CPMAC_OWN;
-               dma_cache_wback_inv((u32)data, len);
-               tail->hw_next = virt_to_phys(curr);
-               tail->next = curr;
-               tail = curr;
-       }
-       tail->hw_next = 0;
-       tail->dataflags |= CPMAC_EOP;
-       dma_cache_wback_inv((u32)tail, 16);
-       priv->regs->tx_ptr[i] = virt_to_phys(head);
+       desc->dataflags = CPMAC_SOP | CPMAC_EOP | CPMAC_OWN;
+       desc->skb = skb;
+       desc->hw_data = virt_to_phys(skb->data);
+       dma_cache_wback((u32)skb->data, len);
+       desc->buflen = len;
+       desc->datalen = len;
+       desc->hw_next = 0;
+       dma_cache_wback((u32)desc, 16);
+       priv->regs->tx_ptr[chan] = virt_to_phys(desc);
        return 0;
 }
 
-void cpmac_end_xmit(struct net_device *dev, int channel)
+static void cpmac_end_xmit(struct net_device *dev, int channel)
 {
-       struct cpmac_desc *pkt;
+       struct cpmac_desc *desc;
        struct cpmac_priv *priv = netdev_priv(dev);
 
        spin_lock(&priv->lock);
-       pkt = priv->tx_channels[channel];
-       priv->tx_channels[channel] = NULL;
-       priv->free_tx_channels++;
-       priv->regs->tx_ack[channel] = virt_to_phys(pkt);
-       if (pkt) {
+       desc = &priv->desc_ring[channel];
+       priv->regs->tx_ack[channel] = virt_to_phys(desc);
+       if (likely(desc->skb)) {
                priv->stats.tx_packets++;
-               priv->stats.tx_bytes += pkt->skb->len;
-               dev_kfree_skb_irq(pkt->skb);
-               cpmac_release_desc(dev, pkt);
-               if (netif_queue_stopped(dev))
-                       netif_wake_queue(dev);
+               priv->stats.tx_bytes += desc->skb->len;
+               dev_kfree_skb_irq(desc->skb);
+               if (priv->tx_head == channel) {
+                       while ((desc->dataflags & CPMAC_OWN) == 0) {
+                               priv->tx_head++;
+                               priv->tx_head %= 8;
+                               if (priv->tx_head == priv->tx_tail)
+                                       break;
+                               desc = &priv->desc_ring[priv->tx_head];
+                       }
+                       if (netif_queue_stopped(dev))
+                               netif_wake_queue(dev);
+               }
        } else {
                if (printk_ratelimit())
                        printk(KERN_NOTICE "%s: end_xmit: spurious interrupt\n",
@@ -530,46 +559,37 @@ static irqreturn_t cpmac_irq(int irq, void *dev_id)
                cpmac_rx(dev, (status >> 8) & 7);
        }
 
-       if (status & INTST_HOST) { /* host interrupt ??? */
+       if (unlikely(status & INTST_HOST)) { /* host interrupt ??? */
                printk("%s: host int, something bad happened...\n", dev->name);
                printk("%s: mac status: 0x%08x\n", dev->name,
                       priv->regs->mac_status);
        }
 
-       if (status & INTST_STATUS) { /* status interrupt ??? */
+       if (unlikely(status & INTST_STATUS)) { /* status interrupt ??? */
                printk("%s: status int, what are we gonna do?\n", dev->name);
        }
 
        priv->regs->mac_eoi_vector = 0;
+
        return IRQ_HANDLED;
 }
 
-void cpmac_tx_timeout(struct net_device *dev)
+static void cpmac_tx_timeout(struct net_device *dev)
 {
-       int i;
        struct cpmac_priv *priv = netdev_priv(dev);
-       struct cpmac_desc *pkt = NULL, *tmp;
+       struct cpmac_desc *desc;
 
        priv->stats.tx_errors++;
-       for (i = 0; i < 8; i++) {
-               tmp = priv->tx_channels[i];
-               if (tmp && (!pkt || (pkt->jiffies > tmp->jiffies)))
-                       pkt = tmp;
-       }
-       if (pkt) {
-               printk("Transmit timeout at %ld, latency %ld\n", jiffies,
-                      jiffies - pkt->jiffies);
-               for (i = 0; i < 8; i++) 
-                       if (priv->tx_channels[i] == pkt)
-                               priv->tx_channels[i] = NULL;
-               dev_kfree_skb(pkt->skb);
-               cpmac_release_desc(dev, pkt);
-               priv->free_tx_channels++;
-               netif_wake_queue(dev);
-       }
+       desc = &priv->desc_ring[priv->tx_head++];
+       priv->tx_head %= 8;
+       printk("Transmit timeout at %ld, latency %ld\n", jiffies,
+              jiffies - desc->jiffies);
+       if (desc->skb)
+               dev_kfree_skb(desc->skb);
+       netif_wake_queue(dev);
 }
 
-int cpmac_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+static int cpmac_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
        struct cpmac_priv *priv = netdev_priv(dev);
        if (!(netif_running(dev)))
@@ -696,16 +716,19 @@ static void cpmac_adjust_link(struct net_device *dev)
        spin_unlock_irqrestore(&priv->lock, flags);
 }
 
-int cpmac_open(struct net_device *dev)
+static int cpmac_open(struct net_device *dev)
 {
-       int i, j, res;
+       int i, size, res;
        struct cpmac_priv *priv = netdev_priv(dev);
-       struct cpmac_desc *pkt;
+       struct cpmac_desc *desc;
        struct sk_buff *skb;
 
-/*     priv->phy = phy_connect(dev, priv->phy_name, &cpmac_adjust_link,
-       0, PHY_INTERFACE_MODE_MII);*/
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
+       priv->phy = phy_connect(dev, priv->phy_name, &cpmac_adjust_link,
+                               0, PHY_INTERFACE_MODE_MII);
+#else
        priv->phy = phy_connect(dev, priv->phy_name, &cpmac_adjust_link, 0);
+#endif
        if (IS_ERR(priv->phy)) {
                printk(KERN_ERR "%s: Could not attach to PHY\n", dev->name);
                return PTR_ERR(priv->phy);
@@ -727,65 +750,65 @@ int cpmac_open(struct net_device *dev)
                goto fail_remap;
        }
 
-       priv->order = get_order(4096);
-       priv->pages = __get_dma_pages(GFP_KERNEL, priv->order);
-       if (!priv->pages) {
+       priv->rx_head = NULL;
+       size = sizeof(struct cpmac_desc) * (CPMAC_RX_RING_SIZE +
+                                           CPMAC_TX_RING_SIZE);
+       priv->desc_ring = (struct cpmac_desc *)kmalloc(size, GFP_KERNEL);
+       if (!priv->desc_ring) {
                res = -ENOMEM;
                goto fail_alloc;
        }
-       memset((char *)priv->pages, 0, 4096);
-
-       priv->tx_pool = NULL;
-
-       for (i = 0; i < 4096 / sizeof(struct cpmac_desc); i++) {
-               pkt = (struct cpmac_desc *)
-                       (priv->pages + i * sizeof(struct cpmac_desc));
-               memset(pkt, sizeof(struct cpmac_desc), 0);
-               if (i < 8) {
-                       skb = alloc_skb(1500 + ETH_HLEN + 6, GFP_KERNEL);
-                       if (!skb) {
-                               for(j = 0; j < i - 1; j++)
-                                       kfree_skb(priv->rx_channels[j]->skb);
-                               free_pages(priv->pages, priv->order);
-                               res = -ENOMEM;
-                               goto fail_alloc;
-                       }
-                       skb_reserve(skb, 2);
-                       skb->dev = dev;
-                       pkt->skb = skb;
-                       pkt->hw_data = virt_to_phys(skb->data);
-                       pkt->buflen = 1500 + ETH_HLEN + 4;
-                       pkt->dataflags = CPMAC_OWN;
-                       dma_cache_wback_inv((u32)pkt, 16);
-                       priv->rx_channels[i] = pkt;
-                       priv->tx_channels[i] = NULL;
-               } else {
-                       pkt->next = priv->tx_pool;
-                       priv->tx_pool = pkt;
+
+       memset((char *)priv->desc_ring, 0, size);
+
+       priv->skb_pool = NULL;
+       priv->free_skbs = 0;
+       priv->rx_head = &priv->desc_ring[CPMAC_TX_RING_SIZE];
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
+        INIT_WORK(&priv->alloc_work, cpmac_alloc_skbs);
+#else
+        INIT_WORK(&priv->alloc_work, cpmac_alloc_skbs, dev);
+#endif
+       schedule_work(&priv->alloc_work);
+       flush_scheduled_work();
+
+       for (i = 0; i < CPMAC_RX_RING_SIZE; i++) {
+               desc = &priv->rx_head[i];
+               skb = cpmac_get_skb(dev);
+               if (!skb) {
+                       res = -ENOMEM;
+                       goto fail_desc;
                }
+               desc->skb = skb;
+               desc->hw_data = virt_to_phys(skb->data);
+               desc->buflen = CPMAC_SKB_SIZE;
+               desc->dataflags = CPMAC_OWN;
+               desc->next = &priv->rx_head[i + 1];
+               desc->hw_next = virt_to_phys(desc->next);
+               dma_cache_wback((u32)desc, 16);
        }
+       priv->rx_head[CPMAC_RX_RING_SIZE - 1].next = priv->rx_head;
+       priv->rx_head[CPMAC_RX_RING_SIZE - 1].hw_next =
+               virt_to_phys(priv->rx_head);
 
        cpmac_reset(dev);
-       priv->free_tx_channels = 8;
-
-       for (i = 0; i < 8; i++) {
+       for (i = 0; i < 8; i++)
                priv->regs->tx_ptr[i] = 0;
-               priv->regs->rx_ptr[i] = virt_to_phys(priv->rx_channels[i]);
-       }
+       priv->regs->rx_ptr[0] = virt_to_phys(priv->rx_head);
 
-       priv->regs->mbp = MBP_RXNOCHAIN | MBP_RXSHORT | MBP_RXBCAST |
-               MBP_RXMCAST;
-       priv->regs->unicast_enable = 0xff;
-       priv->regs->unicast_clear = 0;
+       priv->regs->mbp = MBP_RXSHORT | MBP_RXBCAST | MBP_RXMCAST;
+       priv->regs->unicast_enable = 0x1;
+       priv->regs->unicast_clear = 0xfe;
        priv->regs->buffer_offset = 0;
        for (i = 0; i < 8; i++)
                priv->regs->mac_addr_low[i] = dev->dev_addr[5];
        priv->regs->mac_addr_mid = dev->dev_addr[4];
        priv->regs->mac_addr_high = dev->dev_addr[0] | (dev->dev_addr[1] << 8)
                | (dev->dev_addr[2] << 16) | (dev->dev_addr[3] << 24);
-       priv->regs->max_len = 1536;
-       priv->regs->rx_int.enable = 0xff;
-       priv->regs->rx_int.clear = 0;
+       priv->regs->max_len = CPMAC_SKB_SIZE;
+       priv->regs->rx_int.enable = 0x1;
+       priv->regs->rx_int.clear = 0xfe;
        priv->regs->tx_int.enable = 0xff;
        priv->regs->tx_int.clear = 0;
        priv->regs->mac_int_enable = 3;
@@ -809,12 +832,18 @@ int cpmac_open(struct net_device *dev)
        return 0;
 
 fail_irq:
-       for(i = 0; i < 8; i++)
-               if (priv->rx_channels[i]->skb)
-                       kfree_skb(priv->rx_channels[i]->skb);
-       free_pages(priv->pages, priv->order);
-
+fail_desc:
+       for (i = 0; i < CPMAC_RX_RING_SIZE; i++)
+               if (priv->rx_head[i].skb)
+                       kfree_skb(priv->rx_head[i].skb);
 fail_alloc:
+       kfree(priv->desc_ring);
+
+       for (skb = priv->skb_pool; skb; skb = priv->skb_pool) {
+               priv->skb_pool = skb->next;
+               kfree_skb(skb);
+       }
+
        iounmap(priv->regs);
 
 fail_remap:
@@ -827,9 +856,10 @@ fail_reserve:
        return res;
 }
 
-int cpmac_stop(struct net_device *dev)
+static int cpmac_stop(struct net_device *dev)
 {
        int i;
+       struct sk_buff *skb;
        struct cpmac_priv *priv = netdev_priv(dev);
 
        netif_stop_queue(dev);
@@ -850,18 +880,27 @@ int cpmac_stop(struct net_device *dev)
        release_mem_region(dev->mem_start, dev->mem_end -
                           dev->mem_start);
 
-       for(i = 0; i < 8; i++)
-               if (priv->rx_channels[i]->skb)
-                       kfree_skb(priv->rx_channels[i]->skb);
-       if (priv->pages) 
-               free_pages(priv->pages, priv->order);
+       cancel_delayed_work(&priv->alloc_work);
+       flush_scheduled_work();
+
+       priv->rx_head = &priv->desc_ring[CPMAC_TX_RING_SIZE];
+       for (i = 0; i < CPMAC_RX_RING_SIZE; i++)
+               if (priv->rx_head[i].skb)
+                       kfree_skb(priv->rx_head[i].skb);
+
+       kfree(priv->desc_ring);
+
+       for (skb = priv->skb_pool; skb; skb = priv->skb_pool) {
+               priv->skb_pool = skb->next;
+               kfree_skb(skb);
+       }
 
        return 0;
 }
 
 static int external_switch = 0;
 
-int __devinit cpmac_probe(struct platform_device *pdev)
+static int __devinit cpmac_probe(struct platform_device *pdev)
 {
        int i, rc, phy_id;
        struct resource *res;
@@ -929,6 +968,7 @@ int __devinit cpmac_probe(struct platform_device *pdev)
        spin_lock_init(&priv->lock);
        priv->msg_enable = netif_msg_init(NETIF_MSG_WOL, 0x3fff);
        priv->config = pdata;
+       priv->dev = dev;
        memcpy(dev->dev_addr, priv->config->dev_addr, sizeof(dev->dev_addr));
        if (phy_id == 31) {
                snprintf(priv->phy_name, BUS_ID_SIZE, PHY_ID_FMT,
@@ -988,9 +1028,9 @@ int __devinit cpmac_init(void)
 #warning FIXME: unhardcode gpio&reset bits
        ar7_gpio_disable(26);
        ar7_gpio_disable(27);
-/*     ar7_device_reset(17);
+       ar7_device_reset(17);
        ar7_device_reset(21);
-       ar7_device_reset(26);*/
+       ar7_device_reset(26);
 
        cpmac_mii.reset(&cpmac_mii);