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Commit 7a97bc03 authored by Stefan Richter's avatar Stefan Richter
Browse files

ieee1394: eth1394: handle tlabel exhaustion 

When eth1394 was unable to acquire a transaction label, it just dropped
outgoing packets without attempt to resend them later.

The transmit queue is now halted if no tlabel is available to
->hard_start_xmit().  A workqueue job is then scheduled to catch the
moment when ieee1394 recycled the next lot of tlabels.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=8402



Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 69c29fa7

drivers/ieee1394/eth1394.c

+63 −17
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ 
#include <linux/types.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/workqueue.h>



#include <linux/netdevice.h>

#include <linux/inetdevice.h>
@@ -235,6 +236,9 @@ static int ether1394_open(struct net_device *dev) 
/* This is called after an "ifdown" */

static int ether1394_stop(struct net_device *dev)

{

	/* flush priv->wake */

	flush_scheduled_work();



	netif_stop_queue(dev);

	return 0;

}
@@ -530,6 +534,37 @@ static void ether1394_init_dev(struct net_device *dev) 
	dev->tx_queue_len	= 1000;

}



/*

 * Wake the queue up after commonly encountered transmit failure conditions are

 * hopefully over.  Currently only tlabel exhaustion is accounted for.

 */

static void ether1394_wake_queue(struct work_struct *work)

{

	struct eth1394_priv *priv;

	struct hpsb_packet *packet;



	priv = container_of(work, struct eth1394_priv, wake);

	packet = hpsb_alloc_packet(0);



	/* This is really bad, but unjam the queue anyway. */

	if (!packet)

		goto out;



	packet->host = priv->host;

	packet->node_id = priv->wake_node;

	/*

	 * A transaction label is all we really want.  If we get one, it almost

	 * always means we can get a lot more because the ieee1394 core recycled

	 * a whole batch of tlabels, at last.

	 */

	if (hpsb_get_tlabel(packet) == 0)

		hpsb_free_tlabel(packet);



	hpsb_free_packet(packet);

out:

	netif_wake_queue(priv->wake_dev);

}



/*

 * This function is called every time a card is found. It is generally called

 * when the module is installed. This is where we add all of our ethernet
@@ -574,6 +609,8 @@ static void ether1394_add_host(struct hpsb_host *host) 
	spin_lock_init(&priv->lock);

	priv->host = host;

	priv->local_fifo = fifo_addr;

	INIT_WORK(&priv->wake, ether1394_wake_queue);

	priv->wake_dev = dev;



	hi = hpsb_create_hostinfo(&eth1394_highlevel, host, sizeof(*hi));

	if (hi == NULL) {
@@ -1390,22 +1427,17 @@ static int ether1394_prep_write_packet(struct hpsb_packet *p, 
				       u64 addr, void *data, int tx_len)

{

	p->node_id = node;

	p->data = NULL;



	p->tcode = TCODE_WRITEB;

	p->header[1] = host->node_id << 16 | addr >> 32;

	p->header[2] = addr & 0xffffffff;

	if (hpsb_get_tlabel(p))

		return -EAGAIN;



	p->tcode = TCODE_WRITEB;

	p->header_size = 16;

	p->expect_response = 1;



	if (hpsb_get_tlabel(p)) {

		ETH1394_PRINT_G(KERN_ERR, "Out of tlabels\n");

		return -1;

	}

	p->header[0] =

		p->node_id << 16 | p->tlabel << 10 | 1 << 8 | TCODE_WRITEB << 4;



	p->header[1] = host->node_id << 16 | addr >> 32;

	p->header[2] = addr & 0xffffffff;

	p->header[3] = tx_len << 16;

	p->data_size = (tx_len + 3) & ~3;

	p->data = data;
@@ -1451,7 +1483,7 @@ static int ether1394_send_packet(struct packet_task *ptask, unsigned int tx_len) 


	packet = ether1394_alloc_common_packet(priv->host);

	if (!packet)

		return -1;

		return -ENOMEM;



	if (ptask->tx_type == ETH1394_GASP) {

		int length = tx_len + 2 * sizeof(quadlet_t);
@@ -1462,7 +1494,7 @@ static int ether1394_send_packet(struct packet_task *ptask, unsigned int tx_len) 
					       ptask->addr, ptask->skb->data,

					       tx_len)) {

		hpsb_free_packet(packet);

		return -1;

		return -EAGAIN;

	}



	ptask->packet = packet;
@@ -1471,7 +1503,7 @@ static int ether1394_send_packet(struct packet_task *ptask, unsigned int tx_len) 


	if (hpsb_send_packet(packet) < 0) {

		ether1394_free_packet(packet);

		return -1;

		return -EIO;

	}



	return 0;
@@ -1514,13 +1546,18 @@ static void ether1394_complete_cb(void *__ptask) 


	ptask->outstanding_pkts--;

	if (ptask->outstanding_pkts > 0 && !fail) {

		int tx_len;

		int tx_len, err;



		/* Add the encapsulation header to the fragment */

		tx_len = ether1394_encapsulate(ptask->skb, ptask->max_payload,

					       &ptask->hdr);

		if (ether1394_send_packet(ptask, tx_len))

		err = ether1394_send_packet(ptask, tx_len);

		if (err) {

			if (err == -EAGAIN)

				ETH1394_PRINT_G(KERN_ERR, "Out of tlabels\n");



			ether1394_dg_complete(ptask, 1);

		}

	} else {

		ether1394_dg_complete(ptask, fail);

	}
@@ -1633,9 +1670,18 @@ static int ether1394_tx(struct sk_buff *skb, struct net_device *dev) 
	/* Add the encapsulation header to the fragment */

	tx_len = ether1394_encapsulate(skb, max_payload, &ptask->hdr);

	dev->trans_start = jiffies;

	if (ether1394_send_packet(ptask, tx_len))

	if (ether1394_send_packet(ptask, tx_len)) {

		if (dest_node == (LOCAL_BUS | ALL_NODES))

			goto fail;



		/* Most failures of ether1394_send_packet are recoverable. */

		netif_stop_queue(dev);

		priv->wake_node = dest_node;

		schedule_work(&priv->wake);

		kmem_cache_free(packet_task_cache, ptask);

		return NETDEV_TX_BUSY;

	}



	return NETDEV_TX_OK;

fail:

	if (ptask)

drivers/ieee1394/eth1394.h

+4 −0
Original line number Diff line number Diff line
@@ -66,6 +66,10 @@ struct eth1394_priv { 
	int bc_dgl;			/* Outgoing broadcast datagram label */

	struct list_head ip_node_list;	/* List of IP capable nodes	 */

	struct unit_directory *ud_list[ALL_NODES]; /* Cached unit dir list */



	struct work_struct wake;	/* Wake up after xmit failure	 */

	struct net_device *wake_dev;	/* Stupid backlink for .wake	 */

	nodeid_t wake_node;		/* Destination of failed xmit	 */

};