4 files changed, 35 insertions, 21 deletions

diff --git a/drivers/net/netxen/netxen_nic.h b/drivers/net/netxen/netxen_nic.h
index ab11c2b3f0fe..970cedeb5f37 100644
--- a/drivers/net/netxen/netxen_nic.h
+++ b/drivers/net/netxen/netxen_nic.h
@@ -169,6 +169,7 @@
 #define MAX_NUM_CARDS           4
 
 #define MAX_BUFFERS_PER_CMD     32
+#define TX_STOP_THRESH          ((MAX_SKB_FRAGS >> 2) + 4)
 
 /*
  * Following are the states of the Phantom. Phantom will set them and
@@ -1436,7 +1437,7 @@ int netxen_nic_set_mac(struct net_device *netdev, void *p);
 struct net_device_stats *netxen_nic_get_stats(struct net_device *netdev);
 
 void netxen_nic_update_cmd_producer(struct netxen_adapter *adapter,
-                struct nx_host_tx_ring *tx_ring, uint32_t crb_producer);
+                struct nx_host_tx_ring *tx_ring);
 
 /*
  * NetXen Board information
@@ -1538,6 +1539,14 @@ dma_watchdog_wakeup(struct netxen_adapter *adapter)
 }
 
 
+static inline u32 netxen_tx_avail(struct nx_host_tx_ring *tx_ring)
+{
+        smp_mb();
+        return find_diff_among(tx_ring->producer,
+                        tx_ring->sw_consumer, tx_ring->num_desc);
+
+}
+
 int netxen_get_flash_mac_addr(struct netxen_adapter *adapter, __le64 *mac);
 int netxen_p3_get_mac_addr(struct netxen_adapter *adapter, __le64 *mac);
 extern void netxen_change_ringparam(struct netxen_adapter *adapter);
diff --git a/drivers/net/netxen/netxen_nic_hw.c b/drivers/net/netxen/netxen_nic_hw.c
index 9702509ce3c5..ce3b89d2cbb6 100644
--- a/drivers/net/netxen/netxen_nic_hw.c
+++ b/drivers/net/netxen/netxen_nic_hw.c
@@ -488,7 +488,7 @@ netxen_send_cmd_descs(struct netxen_adapter *adapter,
 
         tx_ring->producer = producer;
 
-        netxen_nic_update_cmd_producer(adapter, tx_ring, producer);
+        netxen_nic_update_cmd_producer(adapter, tx_ring);
 
         netif_tx_unlock_bh(adapter->netdev);
 
diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c
index 6f77ad58e3b3..bdb143d2b5c7 100644
--- a/drivers/net/netxen/netxen_nic_init.c
+++ b/drivers/net/netxen/netxen_nic_init.c
@@ -1292,7 +1292,6 @@ int netxen_process_cmd_ring(struct netxen_adapter *adapter)
                 return 1;
 
         sw_consumer = tx_ring->sw_consumer;
-        barrier(); /* hw_consumer can change underneath */
         hw_consumer = le32_to_cpu(*(tx_ring->hw_consumer));
 
         while (sw_consumer != hw_consumer) {
@@ -1319,14 +1318,15 @@ int netxen_process_cmd_ring(struct netxen_adapter *adapter)
                         break;
         }
 
-        tx_ring->sw_consumer = sw_consumer;
-
         if (count && netif_running(netdev)) {
+                tx_ring->sw_consumer = sw_consumer;
+
                 smp_mb();
+
                 if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev)) {
                         netif_tx_lock(netdev);
-                        netif_wake_queue(netdev);
-                        smp_mb();
+                        if (netxen_tx_avail(tx_ring) > TX_STOP_THRESH)
+                                netif_wake_queue(netdev);
                         netif_tx_unlock(netdev);
                 }
         }
@@ -1343,7 +1343,6 @@ int netxen_process_cmd_ring(struct netxen_adapter *adapter)
          * There is still a possible race condition and the host could miss an
          * interrupt. The card has to take care of this.
          */
-        barrier(); /* hw_consumer can change underneath */
         hw_consumer = le32_to_cpu(*(tx_ring->hw_consumer));
         done = (sw_consumer == hw_consumer);
         spin_unlock(&adapter->tx_clean_lock);
diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c
index 98737ef72936..71daa3d5f114 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -107,9 +107,14 @@ static uint32_t crb_cmd_producer[4] = {
 
 void
 netxen_nic_update_cmd_producer(struct netxen_adapter *adapter,
-                struct nx_host_tx_ring *tx_ring, u32 producer)
+                struct nx_host_tx_ring *tx_ring)
 {
-        NXWR32(adapter, tx_ring->crb_cmd_producer, producer);
+        NXWR32(adapter, tx_ring->crb_cmd_producer, tx_ring->producer);
+
+        if (netxen_tx_avail(tx_ring) <= TX_STOP_THRESH) {
+                netif_stop_queue(adapter->netdev);
+                smp_mb();
+        }
 }
 
 static uint32_t crb_cmd_consumer[4] = {
@@ -119,9 +124,9 @@ static uint32_t crb_cmd_consumer[4] = {
 
 static inline void
 netxen_nic_update_cmd_consumer(struct netxen_adapter *adapter,
-                struct nx_host_tx_ring *tx_ring, u32 consumer)
+                struct nx_host_tx_ring *tx_ring)
 {
-        NXWR32(adapter, tx_ring->crb_cmd_consumer, consumer);
+        NXWR32(adapter, tx_ring->crb_cmd_consumer, tx_ring->sw_consumer);
 }
 
 static uint32_t msi_tgt_status[8] = {
@@ -900,8 +905,11 @@ netxen_nic_attach(struct netxen_adapter *adapter)
                 tx_ring->crb_cmd_producer = crb_cmd_producer[adapter->portnum];
                 tx_ring->crb_cmd_consumer = crb_cmd_consumer[adapter->portnum];
 
-                netxen_nic_update_cmd_producer(adapter, tx_ring, 0);
-                netxen_nic_update_cmd_consumer(adapter, tx_ring, 0);
+                tx_ring->producer = 0;
+                tx_ring->sw_consumer = 0;
+
+                netxen_nic_update_cmd_producer(adapter, tx_ring);
+                netxen_nic_update_cmd_consumer(adapter, tx_ring);
         }
 
         for (ring = 0; ring < adapter->max_rds_rings; ring++) {
@@ -1362,7 +1370,7 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         dma_addr_t temp_dma;
         int i, k;
 
-        u32 producer, consumer;
+        u32 producer;
         int frag_count, no_of_desc;
         u32 num_txd = tx_ring->num_desc;
         bool is_tso = false;
@@ -1372,15 +1380,13 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         /* 4 fragments per cmd des */
         no_of_desc = (frag_count + 3) >> 2;
 
-        producer = tx_ring->producer;
-        smp_mb();
-        consumer = tx_ring->sw_consumer;
-        if ((no_of_desc+2) >= find_diff_among(producer, consumer, num_txd)) {
+        if (unlikely(no_of_desc + 2) > netxen_tx_avail(tx_ring)) {
                 netif_stop_queue(netdev);
-                smp_mb();
                 return NETDEV_TX_BUSY;
         }
 
+        producer = tx_ring->producer;
+
         hwdesc = &tx_ring->desc_head[producer];
         netxen_clear_cmddesc((u64 *)hwdesc);
         pbuf = &tx_ring->cmd_buf_arr[producer];
@@ -1493,7 +1499,7 @@ netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         tx_ring->producer = producer;
         adapter->stats.txbytes += skb->len;
 
-        netxen_nic_update_cmd_producer(adapter, tx_ring, producer);
+        netxen_nic_update_cmd_producer(adapter, tx_ring);
 
         adapter->stats.xmitcalled++;