[PATCH] Remove obsolete code in 8390 driver

The 8390 drivers had provision for using a single Tx buffer,
which was educational back in the day when it served as an
example driver, but it really hasn't been used and can go
away which will make future maintenance easier.

drivers/net/8390.c

@@ -41,6 +41,7 @@
 			  module by all drivers that require it.
   Alan Cox		: Spinlocking work, added 'BUG_83C690'
   Paul Gortmaker	: Separate out Tx timeout code from Tx path.
+  Paul Gortmaker	: Remove old unused single Tx buffer code.
 
   Sources:
   The National Semiconductor LAN Databook, and the 3Com 3c503 databook.
@@ -289,8 +290,6 @@ static int ei_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	send_length = ETH_ZLEN < length ? length : ETH_ZLEN;
     
-#ifdef EI_PINGPONG
-
 	/*
 	 * We have two Tx slots available for use. Find the first free
 	 * slot, and then perform some sanity checks. With two Tx bufs,
@@ -309,7 +308,7 @@ static int ei_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 	else if (ei_local->tx2 == 0) 
 	{
-		output_page = ei_local->tx_start_page + TX_1X_PAGES;
+		output_page = ei_local->tx_start_page + TX_PAGES/2;
 		ei_local->tx2 = send_length;
 		if (ei_debug  &&  ei_local->tx1 > 0)
 			printk(KERN_DEBUG "%s: idle transmitter, tx1=%d, lasttx=%d, txing=%d.\n",
@@ -366,28 +365,6 @@ static int ei_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	else
 		netif_start_queue(dev);
 
-#else	/* EI_PINGPONG */
-
-	/*
-	 * Only one Tx buffer in use. You need two Tx bufs to come close to
-	 * back-to-back transmits. Expect a 20 -> 25% performance hit on
-	 * reasonable hardware if you only use one Tx buffer.
-	 */
-
-	if (length == send_length)
-		ei_block_output(dev, length, skb->data, ei_local->tx_start_page);
-	else {
-		memset(scratch, 0, ETH_ZLEN);
-		memcpy(scratch, skb->data, skb->len);
-		ei_block_output(dev, ETH_ZLEN, scratch, ei_local->tx_start_page);
-	}
-	ei_local->txing = 1;
-	NS8390_trigger_send(dev, send_length, ei_local->tx_start_page);
-	dev->trans_start = jiffies;
-	netif_stop_queue(dev);
-
-#endif	/* EI_PINGPONG */
-
 	/* Turn 8390 interrupts back on. */
 	ei_local->irqlock = 0;
 	outb_p(ENISR_ALL, e8390_base + EN0_IMR);
@@ -590,8 +567,6 @@ static void ei_tx_intr(struct net_device *dev)
     
 	outb_p(ENISR_TX, e8390_base + EN0_ISR); /* Ack intr. */
 
-#ifdef EI_PINGPONG
-
 	/*
 	 * There are two Tx buffers, see which one finished, and trigger
 	 * the send of another one if it exists.
@@ -634,13 +609,6 @@ static void ei_tx_intr(struct net_device *dev)
 //	else printk(KERN_WARNING "%s: unexpected TX-done interrupt, lasttx=%d.\n",
 //			dev->name, ei_local->lasttx);
 
-#else	/* EI_PINGPONG */
-	/*
-	 *  Single Tx buffer: mark it free so another packet can be loaded.
-	 */
-	ei_local->txing = 0;
-#endif
-
 	/* Minimize Tx latency: update the statistics after we restart TXing. */
 	if (status & ENTSR_COL)
 		ei_local->stat.collisions++;

drivers/net/8390.h

@@ -12,17 +12,7 @@
 #include <linux/ioport.h>
 #include <linux/skbuff.h>
 
-#define TX_2X_PAGES 12
-#define TX_1X_PAGES 6
-
-/* Should always use two Tx slots to get back-to-back transmits. */
-#define EI_PINGPONG
-
-#ifdef EI_PINGPONG
-#define TX_PAGES TX_2X_PAGES
-#else
-#define TX_PAGES TX_1X_PAGES
-#endif
+#define TX_PAGES 12	/* Two Tx slots */
 
 #define ETHER_ADDR_LEN 6