*
* Copyright (C) 2003 Ralf Baechle <ralf@linux-mips.org>
*
- * Copyright (C) 2004-2005 MontaVista Software, Inc.
+ * Copyright (C) 2004-2006 MontaVista Software, Inc.
* Dale Farnsworth <dale@farnsworth.org>
*
* Copyright (C) 2004 Steven J. Hill <sjhill1@rockwellcollins.com>
/* UDP change : We may need this */
if ((eth_int_cause_ext & 0x0000ffff) &&
(mv643xx_eth_free_tx_queue(dev, eth_int_cause_ext) == 0) &&
- (mp->tx_ring_size > mp->tx_desc_count + MAX_DESCS_PER_SKB))
+ (mp->tx_ring_size - mp->tx_desc_count > MAX_DESCS_PER_SKB))
netif_wake_queue(dev);
#ifdef MV643XX_NAPI
} else {
mv643xx_eth_update_pscr(dev, &cmd);
if (!netif_carrier_ok(dev)) {
netif_carrier_on(dev);
- if (mp->tx_ring_size > mp->tx_desc_count +
+ if (mp->tx_ring_size - mp->tx_desc_count >
MAX_DESCS_PER_SKB) {
netif_wake_queue(dev);
/* Start TX queue */
mp->tx_curr_desc_q = 0;
mp->tx_used_desc_q = 0;
-#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
- mp->tx_first_desc_q = 0;
-#endif
mp->tx_desc_area_size = tx_desc_num * sizeof(struct eth_tx_desc);
}
if (netif_queue_stopped(dev) &&
- mp->tx_ring_size >
- mp->tx_desc_count + MAX_DESCS_PER_SKB)
+ mp->tx_ring_size - mp->tx_desc_count > MAX_DESCS_PER_SKB)
netif_wake_queue(dev);
}
}
#endif
-/* Hardware can't handle unaligned fragments smaller than 9 bytes.
+/**
+ * has_tiny_unaligned_frags - check if skb has any small, unaligned fragments
+ *
+ * Hardware can't handle unaligned fragments smaller than 9 bytes.
* This helper function detects that case.
*/
return 0;
}
+/**
+ * eth_alloc_tx_desc_index - return the index of the next available tx desc
+ */
+static int eth_alloc_tx_desc_index(struct mv643xx_private *mp)
+{
+ int tx_desc_curr;
+
+ tx_desc_curr = mp->tx_curr_desc_q;
-/*
- * mv643xx_eth_start_xmit
- *
- * This function is queues a packet in the Tx descriptor for
- * required port.
- *
- * Input : skb - a pointer to socket buffer
- * dev - a pointer to the required port
+ BUG_ON(mp->tx_desc_count >= mp->tx_ring_size);
+ mp->tx_desc_count++;
+
+ mp->tx_curr_desc_q = (tx_desc_curr + 1) % mp->tx_ring_size;
+
+ BUG_ON(mp->tx_curr_desc_q == mp->tx_used_desc_q);
+
+ return tx_desc_curr;
+}
+
+/**
+ * eth_tx_fill_frag_descs - fill tx hw descriptors for an skb's fragments.
*
- * Output : zero upon success
+ * Ensure the data for each fragment to be transmitted is mapped properly,
+ * then fill in descriptors in the tx hw queue.
*/
-static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static void eth_tx_fill_frag_descs(struct mv643xx_private *mp,
+ struct sk_buff *skb)
{
- struct mv643xx_private *mp = netdev_priv(dev);
+ int frag;
+ int tx_index;
+ struct eth_tx_desc *desc;
struct net_device_stats *stats = &mp->stats;
- ETH_FUNC_RET_STATUS status;
- unsigned long flags;
- struct pkt_info pkt_info;
- if (netif_queue_stopped(dev)) {
- printk(KERN_ERR
- "%s: Tried sending packet when interface is stopped\n",
- dev->name);
- return 1;
+ for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
+ skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];
+
+ tx_index = eth_alloc_tx_desc_index(mp);
+ desc = &mp->p_tx_desc_area[tx_index];
+
+ desc->cmd_sts = ETH_BUFFER_OWNED_BY_DMA;
+ /* Last Frag enables interrupt and frees the skb */
+ if (frag == (skb_shinfo(skb)->nr_frags - 1)) {
+ desc->cmd_sts |= ETH_ZERO_PADDING |
+ ETH_TX_LAST_DESC |
+ ETH_TX_ENABLE_INTERRUPT;
+ mp->tx_skb[tx_index] = skb;
+ } else
+ mp->tx_skb[tx_index] = 0;
+
+ desc = &mp->p_tx_desc_area[tx_index];
+ desc->l4i_chk = 0;
+ desc->byte_cnt = this_frag->size;
+ desc->buf_ptr = dma_map_page(NULL, this_frag->page,
+ this_frag->page_offset,
+ this_frag->size,
+ DMA_TO_DEVICE);
+ stats->tx_bytes += this_frag->size;
}
+}
- /* This is a hard error, log it. */
- if ((mp->tx_ring_size - mp->tx_desc_count) <=
- (skb_shinfo(skb)->nr_frags + 1)) {
- netif_stop_queue(dev);
- printk(KERN_ERR
- "%s: Bug in mv643xx_eth - Trying to transmit when"
- " queue full !\n", dev->name);
- return 1;
- }
+/**
+ * eth_tx_submit_descs_for_skb - submit data from an skb to the tx hw
+ *
+ * Ensure the data for an skb to be transmitted is mapped properly,
+ * then fill in descriptors in the tx hw queue and start the hardware.
+ */
+static int eth_tx_submit_descs_for_skb(struct mv643xx_private *mp,
+ struct sk_buff *skb)
+{
+ int tx_index;
+ struct eth_tx_desc *desc;
+ u32 cmd_sts;
+ int length;
+ int tx_bytes = 0;
- /* Paranoid check - this shouldn't happen */
- if (skb == NULL) {
- stats->tx_dropped++;
- printk(KERN_ERR "mv64320_eth paranoid check failed\n");
- return 1;
- }
+ cmd_sts = ETH_TX_FIRST_DESC | ETH_GEN_CRC | ETH_BUFFER_OWNED_BY_DMA;
-#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
- if (has_tiny_unaligned_frags(skb)) {
- if ((skb_linearize(skb, GFP_ATOMIC) != 0)) {
- stats->tx_dropped++;
- printk(KERN_DEBUG "%s: failed to linearize tiny "
- "unaligned fragment\n", dev->name);
- return 1;
- }
+ tx_index = eth_alloc_tx_desc_index(mp);
+ desc = &mp->p_tx_desc_area[tx_index];
+
+ if (skb_shinfo(skb)->nr_frags) {
+ eth_tx_fill_frag_descs(mp, skb);
+
+ length = skb_headlen(skb);
+ mp->tx_skb[tx_index] = 0;
+ } else {
+ cmd_sts |= ETH_ZERO_PADDING |
+ ETH_TX_LAST_DESC |
+ ETH_TX_ENABLE_INTERRUPT;
+ length = skb->len;
+ mp->tx_skb[tx_index] = skb;
}
- spin_lock_irqsave(&mp->lock, flags);
+ desc->byte_cnt = length;
+ desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);
+ tx_bytes += length;
- if (!skb_shinfo(skb)->nr_frags) {
- if (skb->ip_summed != CHECKSUM_HW) {
- /* Errata BTS #50, IHL must be 5 if no HW checksum */
- pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT |
- ETH_TX_FIRST_DESC |
- ETH_TX_LAST_DESC |
- 5 << ETH_TX_IHL_SHIFT;
- pkt_info.l4i_chk = 0;
- } else {
- pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT |
- ETH_TX_FIRST_DESC |
- ETH_TX_LAST_DESC |
- ETH_GEN_TCP_UDP_CHECKSUM |
- ETH_GEN_IP_V_4_CHECKSUM |
- skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
- /* CPU already calculated pseudo header checksum. */
- if ((skb->protocol == ETH_P_IP) &&
- (skb->nh.iph->protocol == IPPROTO_UDP) ) {
- pkt_info.cmd_sts |= ETH_UDP_FRAME;
- pkt_info.l4i_chk = skb->h.uh->check;
- } else if ((skb->protocol == ETH_P_IP) &&
- (skb->nh.iph->protocol == IPPROTO_TCP))
- pkt_info.l4i_chk = skb->h.th->check;
- else {
- printk(KERN_ERR
- "%s: chksum proto != IPv4 TCP or UDP\n",
- dev->name);
- spin_unlock_irqrestore(&mp->lock, flags);
- return 1;
- }
+ if (skb->ip_summed == CHECKSUM_HW) {
+ BUG_ON(skb->protocol != ETH_P_IP);
+
+ cmd_sts |= ETH_GEN_TCP_UDP_CHECKSUM |
+ ETH_GEN_IP_V_4_CHECKSUM |
+ skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
+
+ switch (skb->nh.iph->protocol) {
+ case IPPROTO_UDP:
+ cmd_sts |= ETH_UDP_FRAME;
+ desc->l4i_chk = skb->h.uh->check;
+ break;
+ case IPPROTO_TCP:
+ desc->l4i_chk = skb->h.th->check;
+ break;
+ default:
+ BUG();
}
- pkt_info.byte_cnt = skb->len;
- pkt_info.buf_ptr = dma_map_single(NULL, skb->data, skb->len,
- DMA_TO_DEVICE);
- pkt_info.return_info = skb;
- status = eth_port_send(mp, &pkt_info);
- if ((status == ETH_ERROR) || (status == ETH_QUEUE_FULL))
- printk(KERN_ERR "%s: Error on transmitting packet\n",
- dev->name);
- stats->tx_bytes += pkt_info.byte_cnt;
} else {
- unsigned int frag;
-
- /* first frag which is skb header */
- pkt_info.byte_cnt = skb_headlen(skb);
- pkt_info.buf_ptr = dma_map_single(NULL, skb->data,
- skb_headlen(skb),
- DMA_TO_DEVICE);
- pkt_info.l4i_chk = 0;
- pkt_info.return_info = 0;
-
- if (skb->ip_summed != CHECKSUM_HW)
- /* Errata BTS #50, IHL must be 5 if no HW checksum */
- pkt_info.cmd_sts = ETH_TX_FIRST_DESC |
- 5 << ETH_TX_IHL_SHIFT;
- else {
- pkt_info.cmd_sts = ETH_TX_FIRST_DESC |
- ETH_GEN_TCP_UDP_CHECKSUM |
- ETH_GEN_IP_V_4_CHECKSUM |
- skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
- /* CPU already calculated pseudo header checksum. */
- if ((skb->protocol == ETH_P_IP) &&
- (skb->nh.iph->protocol == IPPROTO_UDP)) {
- pkt_info.cmd_sts |= ETH_UDP_FRAME;
- pkt_info.l4i_chk = skb->h.uh->check;
- } else if ((skb->protocol == ETH_P_IP) &&
- (skb->nh.iph->protocol == IPPROTO_TCP))
- pkt_info.l4i_chk = skb->h.th->check;
- else {
- printk(KERN_ERR
- "%s: chksum proto != IPv4 TCP or UDP\n",
- dev->name);
- spin_unlock_irqrestore(&mp->lock, flags);
- return 1;
- }
- }
+ /* Errata BTS #50, IHL must be 5 if no HW checksum */
+ cmd_sts |= 5 << ETH_TX_IHL_SHIFT;
+ desc->l4i_chk = 0;
+ }
- status = eth_port_send(mp, &pkt_info);
- if (status != ETH_OK) {
- if ((status == ETH_ERROR))
- printk(KERN_ERR
- "%s: Error on transmitting packet\n",
- dev->name);
- if (status == ETH_QUEUE_FULL)
- printk("Error on Queue Full \n");
- if (status == ETH_QUEUE_LAST_RESOURCE)
- printk("Tx resource error \n");
- }
- stats->tx_bytes += pkt_info.byte_cnt;
-
- /* Check for the remaining frags */
- for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
- skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];
- pkt_info.l4i_chk = 0x0000;
- pkt_info.cmd_sts = 0x00000000;
-
- /* Last Frag enables interrupt and frees the skb */
- if (frag == (skb_shinfo(skb)->nr_frags - 1)) {
- pkt_info.cmd_sts |= ETH_TX_ENABLE_INTERRUPT |
- ETH_TX_LAST_DESC;
- pkt_info.return_info = skb;
- } else {
- pkt_info.return_info = 0;
- }
- pkt_info.l4i_chk = 0;
- pkt_info.byte_cnt = this_frag->size;
+ /* ensure all other descriptors are written before first cmd_sts */
+ wmb();
+ desc->cmd_sts = cmd_sts;
- pkt_info.buf_ptr = dma_map_page(NULL, this_frag->page,
- this_frag->page_offset,
- this_frag->size,
- DMA_TO_DEVICE);
+ /* ensure all descriptors are written before poking hardware */
+ wmb();
+ mv643xx_eth_port_enable_tx(mp->port_num, mp->port_tx_queue_command);
- status = eth_port_send(mp, &pkt_info);
+ return tx_bytes;
+}
- if (status != ETH_OK) {
- if ((status == ETH_ERROR))
- printk(KERN_ERR "%s: Error on "
- "transmitting packet\n",
- dev->name);
+/**
+ * mv643xx_eth_start_xmit - queue an skb to the hardware for transmission
+ *
+ */
+static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct mv643xx_private *mp = netdev_priv(dev);
+ struct net_device_stats *stats = &mp->stats;
+ unsigned long flags;
- if (status == ETH_QUEUE_LAST_RESOURCE)
- printk("Tx resource error \n");
+ BUG_ON(netif_queue_stopped(dev));
+ BUG_ON(skb == NULL);
+ BUG_ON(mp->tx_ring_size - mp->tx_desc_count < MAX_DESCS_PER_SKB);
- if (status == ETH_QUEUE_FULL)
- printk("Queue is full \n");
- }
- stats->tx_bytes += pkt_info.byte_cnt;
+ if (has_tiny_unaligned_frags(skb)) {
+ if ((skb_linearize(skb, GFP_ATOMIC) != 0)) {
+ stats->tx_dropped++;
+ printk(KERN_DEBUG "%s: failed to linearize tiny "
+ "unaligned fragment\n", dev->name);
+ return 1;
}
}
-#else
- spin_lock_irqsave(&mp->lock, flags);
-
- pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT | ETH_TX_FIRST_DESC |
- ETH_TX_LAST_DESC;
- pkt_info.l4i_chk = 0;
- pkt_info.byte_cnt = skb->len;
- pkt_info.buf_ptr = dma_map_single(NULL, skb->data, skb->len,
- DMA_TO_DEVICE);
- pkt_info.return_info = skb;
- status = eth_port_send(mp, &pkt_info);
- if ((status == ETH_ERROR) || (status == ETH_QUEUE_FULL))
- printk(KERN_ERR "%s: Error on transmitting packet\n",
- dev->name);
- stats->tx_bytes += pkt_info.byte_cnt;
-#endif
- /* Check if TX queue can handle another skb. If not, then
- * signal higher layers to stop requesting TX
- */
- if (mp->tx_ring_size <= (mp->tx_desc_count + MAX_DESCS_PER_SKB))
- /*
- * Stop getting skb's from upper layers.
- * Getting skb's from upper layers will be enabled again after
- * packets are released.
- */
- netif_stop_queue(dev);
+ spin_lock_irqsave(&mp->lock, flags);
- /* Update statistics and start of transmittion time */
+ stats->tx_bytes = eth_tx_submit_descs_for_skb(mp, skb);
stats->tx_packets++;
dev->trans_start = jiffies;
+ if (mp->tx_ring_size - mp->tx_desc_count < MAX_DESCS_PER_SKB)
+ netif_stop_queue(dev);
+
spin_unlock_irqrestore(&mp->lock, flags);
return 0; /* success */
* to the Rx descriptor ring to enable the reuse of this source.
* Return Rx resource is done using the eth_rx_return_buff API.
*
- * Transmit operation:
- * The eth_port_send API supports Scatter-Gather which enables to
- * send a packet spanned over multiple buffers. This means that
- * for each packet info structure given by the user and put into
- * the Tx descriptors ring, will be transmitted only if the 'LAST'
- * bit will be set in the packet info command status field. This
- * API also consider restriction regarding buffer alignments and
- * sizes.
- * The user must return a Tx resource after ensuring the buffer
- * has been transmitted to enable the Tx ring indexes to update.
- *
- * BOARD LAYOUT
- * This device is on-board. No jumper diagram is necessary.
- *
- * EXTERNAL INTERFACE
- *
* Prior to calling the initialization routine eth_port_init() the user
* must set the following fields under mv643xx_private struct:
* port_num User Ethernet port number.
static void eth_port_init(struct mv643xx_private *mp)
{
mp->rx_resource_err = 0;
- mp->tx_resource_err = 0;
eth_port_reset(mp->port_num);
eth_port_write_smi_reg(mp->port_num, location, val);
}
-/*
- * eth_port_send - Send an Ethernet packet
- *
- * DESCRIPTION:
- * This routine send a given packet described by p_pktinfo parameter. It
- * supports transmitting of a packet spaned over multiple buffers. The
- * routine updates 'curr' and 'first' indexes according to the packet
- * segment passed to the routine. In case the packet segment is first,
- * the 'first' index is update. In any case, the 'curr' index is updated.
- * If the routine get into Tx resource error it assigns 'curr' index as
- * 'first'. This way the function can abort Tx process of multiple
- * descriptors per packet.
- *
- * INPUT:
- * struct mv643xx_private *mp Ethernet Port Control srtuct.
- * struct pkt_info *p_pkt_info User packet buffer.
- *
- * OUTPUT:
- * Tx ring 'curr' and 'first' indexes are updated.
- *
- * RETURN:
- * ETH_QUEUE_FULL in case of Tx resource error.
- * ETH_ERROR in case the routine can not access Tx desc ring.
- * ETH_QUEUE_LAST_RESOURCE if the routine uses the last Tx resource.
- * ETH_OK otherwise.
- *
- */
-#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
-/*
- * Modified to include the first descriptor pointer in case of SG
- */
-static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
- struct pkt_info *p_pkt_info)
-{
- int tx_desc_curr, tx_desc_used, tx_first_desc, tx_next_desc;
- struct eth_tx_desc *current_descriptor;
- struct eth_tx_desc *first_descriptor;
- u32 command;
-
- /* Do not process Tx ring in case of Tx ring resource error */
- if (mp->tx_resource_err)
- return ETH_QUEUE_FULL;
-
- /*
- * The hardware requires that each buffer that is <= 8 bytes
- * in length must be aligned on an 8 byte boundary.
- */
- if (p_pkt_info->byte_cnt <= 8 && p_pkt_info->buf_ptr & 0x7) {
- printk(KERN_ERR
- "mv643xx_eth port %d: packet size <= 8 problem\n",
- mp->port_num);
- return ETH_ERROR;
- }
-
- mp->tx_desc_count++;
- BUG_ON(mp->tx_desc_count > mp->tx_ring_size);
-
- /* Get the Tx Desc ring indexes */
- tx_desc_curr = mp->tx_curr_desc_q;
- tx_desc_used = mp->tx_used_desc_q;
-
- current_descriptor = &mp->p_tx_desc_area[tx_desc_curr];
-
- tx_next_desc = (tx_desc_curr + 1) % mp->tx_ring_size;
-
- current_descriptor->buf_ptr = p_pkt_info->buf_ptr;
- current_descriptor->byte_cnt = p_pkt_info->byte_cnt;
- current_descriptor->l4i_chk = p_pkt_info->l4i_chk;
- mp->tx_skb[tx_desc_curr] = p_pkt_info->return_info;
-
- command = p_pkt_info->cmd_sts | ETH_ZERO_PADDING | ETH_GEN_CRC |
- ETH_BUFFER_OWNED_BY_DMA;
- if (command & ETH_TX_FIRST_DESC) {
- tx_first_desc = tx_desc_curr;
- mp->tx_first_desc_q = tx_first_desc;
- first_descriptor = current_descriptor;
- mp->tx_first_command = command;
- } else {
- tx_first_desc = mp->tx_first_desc_q;
- first_descriptor = &mp->p_tx_desc_area[tx_first_desc];
- BUG_ON(first_descriptor == NULL);
- current_descriptor->cmd_sts = command;
- }
-
- if (command & ETH_TX_LAST_DESC) {
- wmb();
- first_descriptor->cmd_sts = mp->tx_first_command;
-
- wmb();
- mv643xx_eth_port_enable_tx(mp->port_num, mp->port_tx_queue_command);
-
- /*
- * Finish Tx packet. Update first desc in case of Tx resource
- * error */
- tx_first_desc = tx_next_desc;
- mp->tx_first_desc_q = tx_first_desc;
- }
-
- /* Check for ring index overlap in the Tx desc ring */
- if (tx_next_desc == tx_desc_used) {
- mp->tx_resource_err = 1;
- mp->tx_curr_desc_q = tx_first_desc;
-
- return ETH_QUEUE_LAST_RESOURCE;
- }
-
- mp->tx_curr_desc_q = tx_next_desc;
-
- return ETH_OK;
-}
-#else
-static ETH_FUNC_RET_STATUS eth_port_send(struct mv643xx_private *mp,
- struct pkt_info *p_pkt_info)
-{
- int tx_desc_curr;
- int tx_desc_used;
- struct eth_tx_desc *current_descriptor;
- unsigned int command_status;
-
- /* Do not process Tx ring in case of Tx ring resource error */
- if (mp->tx_resource_err)
- return ETH_QUEUE_FULL;
-
- mp->tx_desc_count++;
- BUG_ON(mp->tx_desc_count > mp->tx_ring_size);
-
- /* Get the Tx Desc ring indexes */
- tx_desc_curr = mp->tx_curr_desc_q;
- tx_desc_used = mp->tx_used_desc_q;
- current_descriptor = &mp->p_tx_desc_area[tx_desc_curr];
-
- command_status = p_pkt_info->cmd_sts | ETH_ZERO_PADDING | ETH_GEN_CRC;
- current_descriptor->buf_ptr = p_pkt_info->buf_ptr;
- current_descriptor->byte_cnt = p_pkt_info->byte_cnt;
- mp->tx_skb[tx_desc_curr] = p_pkt_info->return_info;
-
- /* Set last desc with DMA ownership and interrupt enable. */
- wmb();
- current_descriptor->cmd_sts = command_status |
- ETH_BUFFER_OWNED_BY_DMA | ETH_TX_ENABLE_INTERRUPT;
-
- wmb();
- mv643xx_eth_port_enable_tx(mp->port_num, mp->port_tx_queue_command);
-
- /* Finish Tx packet. Update first desc in case of Tx resource error */
- tx_desc_curr = (tx_desc_curr + 1) % mp->tx_ring_size;
-
- /* Update the current descriptor */
- mp->tx_curr_desc_q = tx_desc_curr;
-
- /* Check for ring index overlap in the Tx desc ring */
- if (tx_desc_curr == tx_desc_used) {
- mp->tx_resource_err = 1;
- return ETH_QUEUE_LAST_RESOURCE;
- }
-
- return ETH_OK;
-}
-#endif
-
/*
* eth_tx_return_desc - Free all used Tx descriptors
*
struct pkt_info *p_pkt_info)
{
int tx_desc_used;
- int tx_busy_desc;
struct eth_tx_desc *p_tx_desc_used;
unsigned int command_status;
unsigned long flags;
spin_lock_irqsave(&mp->lock, flags);
-#ifdef MV643XX_CHECKSUM_OFFLOAD_TX
- tx_busy_desc = mp->tx_first_desc_q;
-#else
- tx_busy_desc = mp->tx_curr_desc_q;
-#endif
+ BUG_ON(mp->tx_desc_count < 0);
+ if (mp->tx_desc_count == 0) {
+ /* no more tx descs in use */
+ err = ETH_ERROR;
+ goto out;
+ }
/* Get the Tx Desc ring indexes */
tx_desc_used = mp->tx_used_desc_q;
p_tx_desc_used = &mp->p_tx_desc_area[tx_desc_used];
- /* Sanity check */
- if (p_tx_desc_used == NULL) {
- err = ETH_ERROR;
- goto out;
- }
-
- /* Stop release. About to overlap the current available Tx descriptor */
- if (tx_desc_used == tx_busy_desc && !mp->tx_resource_err) {
- err = ETH_ERROR;
- goto out;
- }
+ BUG_ON(p_tx_desc_used == NULL);
command_status = p_tx_desc_used->cmd_sts;
-
- /* Still transmitting... */
if (command_status & (ETH_BUFFER_OWNED_BY_DMA)) {
+ /* Still transmitting... */
err = ETH_ERROR;
goto out;
}
/* Update the next descriptor to release. */
mp->tx_used_desc_q = (tx_desc_used + 1) % mp->tx_ring_size;
- /* Any Tx return cancels the Tx resource error status */
- mp->tx_resource_err = 0;
-
BUG_ON(mp->tx_desc_count == 0);
mp->tx_desc_count--;
projects / linux-2.6 / commitdiff