[PATCH v2, resend] gianfar: don't duplicate gfar_error()

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

It was hardly necessary to repeat most of the code from gfar_error() in
gfar_interrupt(), especially having some inconsistencies between the two.
So, make the gfar_interrupt() just call gfar_error(), and not acknowledge
the interrupts itself as gfar_{receive/transmit/error}() do it anyway.
While at it, also clarify/cleanup debug messages in gfar_error()...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>

---
The patch survived netperf stressing on MPC8540ADS realtime kernel. :-)

Sorry, forgot to remove the obsolete regs argument from gfar_error() call,
call, so the previous version wasn't even compilable -- I've tested the patch
in the older kernel. Resending now with better placed comments which you won't
have to edit out... :-<

 drivers/net/gianfar.c |   85 ++++++++------------------------------------------
 1 files changed, 15 insertions(+), 70 deletions(-)

Index: linux-2.6/drivers/net/gianfar.c
===================================================================
--- linux-2.6.orig/drivers/net/gianfar.c
+++ linux-2.6/drivers/net/gianfar.c
@@ -10,6 +10,7 @@
  * Maintainer: Kumar Gala
  *
  * Copyright (c) 2002-2006 Freescale Semiconductor, Inc.
+ * Copyright (c) 2007 MontaVista Software, Inc.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -1613,71 +1614,17 @@ static irqreturn_t gfar_interrupt(int ir
 	/* Save ievent for future reference */
 	u32 events = gfar_read(&priv->regs->ievent);
 
-	/* Clear IEVENT */
-	gfar_write(&priv->regs->ievent, events);
-
 	/* Check for reception */
-	if ((events & IEVENT_RXF0) || (events & IEVENT_RXB0))
+	if (events & IEVENT_RX_MASK)
 		gfar_receive(irq, dev_id);
 
 	/* Check for transmit completion */
-	if ((events & IEVENT_TXF) || (events & IEVENT_TXB))
+	if (events & IEVENT_TX_MASK)
 		gfar_transmit(irq, dev_id);
 
-	/* Update error statistics */
-	if (events & IEVENT_TXE) {
-		priv->stats.tx_errors++;
-
-		if (events & IEVENT_LC)
-			priv->stats.tx_window_errors++;
-		if (events & IEVENT_CRL)
-			priv->stats.tx_aborted_errors++;
-		if (events & IEVENT_XFUN) {
-			if (netif_msg_tx_err(priv))
-				printk(KERN_WARNING "%s: tx underrun. dropped packet\n", dev->name);
-			priv->stats.tx_dropped++;
-			priv->extra_stats.tx_underrun++;
-
-			/* Reactivate the Tx Queues */
-			gfar_write(&priv->regs->tstat, TSTAT_CLEAR_THALT);
-		}
-	}
-	if (events & IEVENT_BSY) {
-		priv->stats.rx_errors++;
-		priv->extra_stats.rx_bsy++;
-
-		gfar_receive(irq, dev_id);
-
-#ifndef CONFIG_GFAR_NAPI
-		/* Clear the halt bit in RSTAT */
-		gfar_write(&priv->regs->rstat, RSTAT_CLEAR_RHALT);
-#endif
-
-		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: busy error (rhalt: %x)\n",
-					dev->name,
-					gfar_read(&priv->regs->rstat));
-	}
-	if (events & IEVENT_BABR) {
-		priv->stats.rx_errors++;
-		priv->extra_stats.rx_babr++;
-
-		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: babbling error\n", dev->name);
-	}
-	if (events & IEVENT_EBERR) {
-		priv->extra_stats.eberr++;
-		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: EBERR\n", dev->name);
-	}
-	if ((events & IEVENT_RXC) && (netif_msg_rx_err(priv)))
-			printk(KERN_DEBUG "%s: control frame\n", dev->name);
-
-	if (events & IEVENT_BABT) {
-		priv->extra_stats.tx_babt++;
-		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: babt error\n", dev->name);
-	}
+	/* Check for errors */
+	if (events & IEVENT_ERR_MASK)
+		gfar_error(irq, dev_id);
 
 	return IRQ_HANDLED;
 }
@@ -1939,7 +1886,7 @@ static irqreturn_t gfar_error(int irq, v
 	/* Hmm... */
 	if (netif_msg_rx_err(priv) || netif_msg_tx_err(priv))
 		printk(KERN_DEBUG "%s: error interrupt (ievent=0x%08x imask=0x%08x)\n",
-				dev->name, events, gfar_read(&priv->regs->imask));
+		       dev->name, events, gfar_read(&priv->regs->imask));
 
 	/* Update the error counters */
 	if (events & IEVENT_TXE) {
@@ -1951,8 +1898,8 @@ static irqreturn_t gfar_error(int irq, v
 			priv->stats.tx_aborted_errors++;
 		if (events & IEVENT_XFUN) {
 			if (netif_msg_tx_err(priv))
-				printk(KERN_DEBUG "%s: underrun.  packet dropped.\n",
-						dev->name);
+				printk(KERN_DEBUG "%s: TX FIFO underrun, "
+				       "packet dropped.\n", dev->name);
 			priv->stats.tx_dropped++;
 			priv->extra_stats.tx_underrun++;
 
@@ -1974,30 +1921,28 @@ static irqreturn_t gfar_error(int irq, v
 #endif
 
 		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: busy error (rhalt: %x)\n",
-					dev->name,
-					gfar_read(&priv->regs->rstat));
+			printk(KERN_DEBUG "%s: busy error (rstat: %x)\n",
+			       dev->name, gfar_read(&priv->regs->rstat));
 	}
 	if (events & IEVENT_BABR) {
 		priv->stats.rx_errors++;
 		priv->extra_stats.rx_babr++;
 
 		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: babbling error\n", dev->name);
+			printk(KERN_DEBUG "%s: babbling RX error\n", dev->name);
 	}
 	if (events & IEVENT_EBERR) {
 		priv->extra_stats.eberr++;
 		if (netif_msg_rx_err(priv))
-			printk(KERN_DEBUG "%s: EBERR\n", dev->name);
+			printk(KERN_DEBUG "%s: bus error\n", dev->name);
 	}
 	if ((events & IEVENT_RXC) && netif_msg_rx_status(priv))
-		if (netif_msg_rx_status(priv))
-			printk(KERN_DEBUG "%s: control frame\n", dev->name);
+		printk(KERN_DEBUG "%s: control frame\n", dev->name);
 
 	if (events & IEVENT_BABT) {
 		priv->extra_stats.tx_babt++;
 		if (netif_msg_tx_err(priv))
-			printk(KERN_DEBUG "%s: babt error\n", dev->name);
+			printk(KERN_DEBUG "%s: babbling TX error\n", dev->name);
 	}
 	return IRQ_HANDLED;
 }