netxen: optimize tx handling

netxen driver allows limited number of threads simultaneously posting
skb's in tx ring. If transmit slot is unavailable, driver calls
schedule() or loops in xmit_frame().

This patch returns TX_BUSY and lets the stack reschedule the packet if
transmit slot is unavailable. Also removes unnecessary check for tx
timeout in the driver itself, the network stack does that anyway.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/net/netxen/netxen_nic_init.c b/drivers/net/netxen/netxen_nic_init.c
index 37589265297e..5f85ad686c98 100644
--- a/drivers/net/netxen/netxen_nic_init.c
+++ b/drivers/net/netxen/netxen_nic_init.c
@@ -1248,7 +1248,6 @@ int netxen_process_cmd_ring(unsigned long data)
         struct pci_dev *pdev;
         struct netxen_skb_frag *frag;
         u32 i;
-        struct sk_buff *skb = NULL;
         int done;
 
         spin_lock(&adapter->tx_lock);
@@ -1278,9 +1277,8 @@ int netxen_process_cmd_ring(unsigned long data)
         while ((last_consumer != consumer) && (count1 < MAX_STATUS_HANDLE)) {
                 buffer = &adapter->cmd_buf_arr[last_consumer];
                 pdev = adapter->pdev;
-                frag = &buffer->frag_array[0];
-                skb = buffer->skb;
-                if (skb && (cmpxchg(&buffer->skb, skb, 0) == skb)) {
+                if (buffer->skb) {
+                        frag = &buffer->frag_array[0];
                         pci_unmap_single(pdev, frag->dma, frag->length,
                                          PCI_DMA_TODEVICE);
                         frag->dma = 0ULL;
@@ -1293,8 +1291,8 @@ int netxen_process_cmd_ring(unsigned long data)
                         }
 
                         adapter->stats.skbfreed++;
-                        dev_kfree_skb_any(skb);
-                        skb = NULL;
+                        dev_kfree_skb_any(buffer->skb);
+                        buffer->skb = NULL;
                 } else if (adapter->proc_cmd_buf_counter == 1) {
                         adapter->stats.txnullskb++;
                 }