Merge branch 'fwnet' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6

* 'fwnet' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: net: throttle TX queue before running out of tlabels
firewire: net: replace lists by counters
firewire: net: fix memory leaks
firewire: net: count stats.tx_packets and stats.tx_bytes

drivers/firewire/net.c

···
  */
 
 #include <linux/bug.h>
+#include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/firewire.h>
 #include <linux/firewire-constants.h>
···
 #include <asm/unaligned.h>
 #include <net/arp.h>
 
-#define FWNET_MAX_FRAGMENTS	25	/* arbitrary limit */
-#define FWNET_ISO_PAGE_COUNT	(PAGE_SIZE < 16 * 1024 ? 4 : 2)
+/* rx limits */
+#define FWNET_MAX_FRAGMENTS		30 /* arbitrary, > TX queue depth */
+#define FWNET_ISO_PAGE_COUNT		(PAGE_SIZE < 16*1024 ? 4 : 2)
+
+/* tx limits */
+#define FWNET_MAX_QUEUED_DATAGRAMS	20 /* < 64 = number of tlabels */
+#define FWNET_MIN_QUEUED_DATAGRAMS	10 /* should keep AT DMA busy enough */
+#define FWNET_TX_QUEUE_LEN		FWNET_MAX_QUEUED_DATAGRAMS /* ? */
 
 #define IEEE1394_BROADCAST_CHANNEL	31
 #define IEEE1394_ALL_NODES		(0xffc0 | 0x003f)
···
 	struct fw_address_handler handler;
 	u64 local_fifo;
 
-	/* List of packets to be sent */
-	struct list_head packet_list;
-	/*
-	 * List of packets that were broadcasted.  When we get an ISO interrupt
-	 * one of them has been sent
-	 */
-	struct list_head broadcasted_list;
-	/* List of packets that have been sent but not yet acked */
-	struct list_head sent_list;
+	/* Number of tx datagrams that have been queued but not yet acked */
+	int queued_datagrams;
 
 	struct list_head peer_list;
 	struct fw_card *card;
···
 	unsigned pdg_size;        /* pd_list size */
 
 	u16 datagram_label;       /* outgoing datagram label */
-	unsigned max_payload;     /* includes RFC2374_FRAG_HDR_SIZE overhead */
+	u16 max_payload;          /* includes RFC2374_FRAG_HDR_SIZE overhead */
 	int node_id;
 	int generation;
 	unsigned speed;
···
 
 /* This is our task struct. It's used for the packet complete callback.  */
 struct fwnet_packet_task {
-	/*
-	 * ptask can actually be on dev->packet_list, dev->broadcasted_list,
-	 * or dev->sent_list depending on its current state.
-	 */
-	struct list_head pt_link;
 	struct fw_transaction transaction;
 	struct rfc2734_header hdr;
 	struct sk_buff *skb;
 	struct fwnet_device *dev;
 
 	int outstanding_pkts;
-	unsigned max_payload;
 	u64 fifo_addr;
 	u16 dest_node;
+	u16 max_payload;
 	u8 generation;
 	u8 speed;
+	u8 enqueued;
 };
 
 /*
···
 		net->stats.rx_packets++;
 		net->stats.rx_bytes += skb->len;
 	}
-	if (netif_queue_stopped(net))
-		netif_wake_queue(net);
 
 	return 0;
 
···
 	net->stats.rx_dropped++;
 
 	dev_kfree_skb_any(skb);
-	if (netif_queue_stopped(net))
-		netif_wake_queue(net);
 
 	return -ENOENT;
 }
···
 	 * Datagram is not complete, we're done for the
 	 * moment.
 	 */
-	spin_unlock_irqrestore(&dev->lock, flags);
-
-	return 0;
+	retval = 0;
  fail:
 	spin_unlock_irqrestore(&dev->lock, flags);
-
-	if (netif_queue_stopped(net))
-		netif_wake_queue(net);
 
 	return retval;
 }
···
 	kmem_cache_free(fwnet_packet_task_cache, ptask);
 }
 
+/* Caller must hold dev->lock. */
+static void dec_queued_datagrams(struct fwnet_device *dev)
+{
+	if (--dev->queued_datagrams == FWNET_MIN_QUEUED_DATAGRAMS)
+		netif_wake_queue(dev->netdev);
+}
+
 static int fwnet_send_packet(struct fwnet_packet_task *ptask);
 
 static void fwnet_transmit_packet_done(struct fwnet_packet_task *ptask)
 {
 	struct fwnet_device *dev = ptask->dev;
+	struct sk_buff *skb = ptask->skb;
 	unsigned long flags;
 	bool free;
 
···
 	ptask->outstanding_pkts--;
 
 	/* Check whether we or the networking TX soft-IRQ is last user. */
-	free = (ptask->outstanding_pkts == 0 && !list_empty(&ptask->pt_link));
+	free = (ptask->outstanding_pkts == 0 && ptask->enqueued);
+	if (free)
+		dec_queued_datagrams(dev);
 
-	if (ptask->outstanding_pkts == 0)
-		list_del(&ptask->pt_link);
+	if (ptask->outstanding_pkts == 0) {
+		dev->netdev->stats.tx_packets++;
+		dev->netdev->stats.tx_bytes += skb->len;
+	}
 
 	spin_unlock_irqrestore(&dev->lock, flags);
 
···
 		u16 fg_off;
 		u16 datagram_label;
 		u16 lf;
-		struct sk_buff *skb;
 
 		/* Update the ptask to point to the next fragment and send it */
 		lf = fwnet_get_hdr_lf(&ptask->hdr);
···
 			datagram_label = fwnet_get_hdr_dgl(&ptask->hdr);
 			break;
 		}
-		skb = ptask->skb;
+
 		skb_pull(skb, ptask->max_payload);
 		if (ptask->outstanding_pkts > 1) {
 			fwnet_make_sf_hdr(&ptask->hdr, RFC2374_HDR_INTFRAG,
···
 		fwnet_free_ptask(ptask);
 }
 
+static void fwnet_transmit_packet_failed(struct fwnet_packet_task *ptask)
+{
+	struct fwnet_device *dev = ptask->dev;
+	unsigned long flags;
+	bool free;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* One fragment failed; don't try to send remaining fragments. */
+	ptask->outstanding_pkts = 0;
+
+	/* Check whether we or the networking TX soft-IRQ is last user. */
+	free = ptask->enqueued;
+	if (free)
+		dec_queued_datagrams(dev);
+
+	dev->netdev->stats.tx_dropped++;
+	dev->netdev->stats.tx_errors++;
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	if (free)
+		fwnet_free_ptask(ptask);
+}
+
 static void fwnet_write_complete(struct fw_card *card, int rcode,
 				 void *payload, size_t length, void *data)
 {
···
 
 	ptask = data;
 
-	if (rcode == RCODE_COMPLETE)
+	if (rcode == RCODE_COMPLETE) {
 		fwnet_transmit_packet_done(ptask);
-	else
+	} else {
 		fw_error("fwnet_write_complete: failed: %x\n", rcode);
-		/* ??? error recovery */
+		fwnet_transmit_packet_failed(ptask);
+	}
 }
 
 static int fwnet_send_packet(struct fwnet_packet_task *ptask)
···
 		spin_lock_irqsave(&dev->lock, flags);
 
 		/* If the AT tasklet already ran, we may be last user. */
-		free = (ptask->outstanding_pkts == 0 && list_empty(&ptask->pt_link));
+		free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
 		if (!free)
-			list_add_tail(&ptask->pt_link, &dev->broadcasted_list);
+			ptask->enqueued = true;
+		else
+			dec_queued_datagrams(dev);
 
 		spin_unlock_irqrestore(&dev->lock, flags);
 
···
 	spin_lock_irqsave(&dev->lock, flags);
 
 	/* If the AT tasklet already ran, we may be last user. */
-	free = (ptask->outstanding_pkts == 0 && list_empty(&ptask->pt_link));
+	free = (ptask->outstanding_pkts == 0 && !ptask->enqueued);
 	if (!free)
-		list_add_tail(&ptask->pt_link, &dev->sent_list);
+		ptask->enqueued = true;
+	else
+		dec_queued_datagrams(dev);
 
 	spin_unlock_irqrestore(&dev->lock, flags);
 
···
 	struct fwnet_peer *peer;
 	unsigned long flags;
 
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* Can this happen? */
+	if (netif_queue_stopped(dev->netdev)) {
+		spin_unlock_irqrestore(&dev->lock, flags);
+
+		return NETDEV_TX_BUSY;
+	}
+
 	ptask = kmem_cache_alloc(fwnet_packet_task_cache, GFP_ATOMIC);
 	if (ptask == NULL)
 		goto fail;
···
 
 	proto = hdr_buf.h_proto;
 	dg_size = skb->len;
-
-	/* serialize access to peer, including peer->datagram_label */
-	spin_lock_irqsave(&dev->lock, flags);
 
 	/*
 	 * Set the transmission type for the packet.  ARP packets and IP
···
 
 		peer = fwnet_peer_find_by_guid(dev, be64_to_cpu(guid));
 		if (!peer || peer->fifo == FWNET_NO_FIFO_ADDR)
-			goto fail_unlock;
+			goto fail;
 
 		generation         = peer->generation;
 		dest_node          = peer->node_id;
···
 		max_payload += RFC2374_FRAG_HDR_SIZE;
 	}
 
+	if (++dev->queued_datagrams == FWNET_MAX_QUEUED_DATAGRAMS)
+		netif_stop_queue(dev->netdev);
+
 	spin_unlock_irqrestore(&dev->lock, flags);
 
 	ptask->max_payload = max_payload;
-	INIT_LIST_HEAD(&ptask->pt_link);
+	ptask->enqueued    = 0;
 
 	fwnet_send_packet(ptask);
 
 	return NETDEV_TX_OK;
 
- fail_unlock:
-	spin_unlock_irqrestore(&dev->lock, flags);
  fail:
+	spin_unlock_irqrestore(&dev->lock, flags);
+
 	if (ptask)
 		kmem_cache_free(fwnet_packet_task_cache, ptask);
 
···
 	net->addr_len		= FWNET_ALEN;
 	net->hard_header_len	= FWNET_HLEN;
 	net->type		= ARPHRD_IEEE1394;
-	net->tx_queue_len	= 10;
+	net->tx_queue_len	= FWNET_TX_QUEUE_LEN;
 }
 
 /* caller must hold fwnet_device_mutex */
···
 	dev->broadcast_rcv_context = NULL;
 	dev->broadcast_xmt_max_payload = 0;
 	dev->broadcast_xmt_datagramlabel = 0;
-
 	dev->local_fifo = FWNET_NO_FIFO_ADDR;
-
-	INIT_LIST_HEAD(&dev->packet_list);
-	INIT_LIST_HEAD(&dev->broadcasted_list);
-	INIT_LIST_HEAD(&dev->sent_list);
+	dev->queued_datagrams = 0;
 	INIT_LIST_HEAD(&dev->peer_list);
-
 	dev->card = card;
 	dev->netdev = net;
 
···
 	struct fwnet_peer *peer = dev_get_drvdata(_dev);
 	struct fwnet_device *dev = peer->dev;
 	struct net_device *net;
-	struct fwnet_packet_task *ptask, *pt_next;
+	int i;
 
 	mutex_lock(&fwnet_device_mutex);
 
···
 					      dev->card);
 			fw_iso_context_destroy(dev->broadcast_rcv_context);
 		}
-		list_for_each_entry_safe(ptask, pt_next,
-					 &dev->packet_list, pt_link) {
-			dev_kfree_skb_any(ptask->skb);
-			kmem_cache_free(fwnet_packet_task_cache, ptask);
-		}
-		list_for_each_entry_safe(ptask, pt_next,
-					 &dev->broadcasted_list, pt_link) {
-			dev_kfree_skb_any(ptask->skb);
-			kmem_cache_free(fwnet_packet_task_cache, ptask);
-		}
-		list_for_each_entry_safe(ptask, pt_next,
-					 &dev->sent_list, pt_link) {
-			dev_kfree_skb_any(ptask->skb);
-			kmem_cache_free(fwnet_packet_task_cache, ptask);
-		}
+		for (i = 0; dev->queued_datagrams && i < 5; i++)
+			ssleep(1);
+		WARN_ON(dev->queued_datagrams);
 		list_del(&dev->dev_link);
 
 		free_netdev(net);