PATCH dm9ks interrupt handling

I was having problems with the OSD not receiving packets on a busy
network. Typically I would notice this when a telnet session hung for
5-15 seconds when I pressed a key, but it also happened in many other
circumstances.

I discovered that the driver had some code that disabled the receive
interrupt after 10 packets were received. The interrupt would be re-
enabled by completing a transmit or by a 5 second timer. This somewhat
crazy code was presumably designed to reduce the load on the processor
(or maybe the IRQ system) when the device is not actively
communicating. However, on a network with a moderate amount of
broadcast traffic it was very common for the device to stop receiving
for several seconds and then overrun its receive buffer when the
interrupt was re-enabled.

I have removed this mechanism and also removed the bogus ioctl handler
that just returned success to all calls, which makes things like the
mii interface look like they work, but always return junk!

Patch below.

Chris.

--- dm9ks.c.orig	2007-03-06 15:10:23.000000000 +0000
+++ dm9ks.c	2007-03-06 15:15:16.000000000 +0000
@@ -37,6 +37,8 @@
 V2.03	11/22/2005	Power-off and Power-on PHY in dmfe_init()
 			support IOL
 06/17/2006	Butchered for NTR3 OSD
+        06/Mar/2007 Removed masking of RX interrupt when not
transmitting
+                    Removed ioctl handler which just said OK!
 */

 #if defined(MODVERSIONS)
@@ -121,11 +123,6 @@
 #define DATAOFST1   2           /* OSD:use A0 as CMD line */
 #define DATAOFST2   0x10000     /* OSD:use A15 as CMD line */

-/* Number of continuous Rx packets */
-#define CONT_RX_PKT_CNT	10
-
-#define DMFE_TIMER_WUT  jiffies+(HZ*5)	/* timer wakeup time : 5
second */
-
 #define CARDNAME "dm9ks"

 #define	MEM_MAPPED_IO	1
@@ -198,8 +195,6 @@
 	u8 device_wait_reset;		/* device state */
 	u8 Speed;			/* current speed */

-	int cont_rx_pkt_cnt;/* current number of continuos rx packets  */
-	struct timer_list timer;
 	struct net_device_stats stats;
 	unsigned char srom[128];
 	spinlock_t lock;
@@ -222,13 +217,11 @@
 static void dmfe_packet_receive(struct net_device *);
 static int dmfe_stop(struct net_device *);
 static struct net_device_stats * dmfe_get_stats(struct net_device
*);
-static int dmfe_do_ioctl(struct net_device *, struct ifreq *, int);
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0)
 static void dmfe_interrupt(int , void *, struct pt_regs *);
 #else
 static irqreturn_t dmfe_interrupt(int , void *, struct pt_regs *);
 #endif
-static void dmfe_timer(unsigned long);
 static void dmfe_init_dm9000(struct net_device *);
 static unsigned long cal_CRC(unsigned char *, unsigned int, u8);
 static u8 ior(board_info_t *, int);
@@ -311,7 +304,6 @@
 	dev->stop 		= &dmfe_stop;
 	dev->get_stats 		= &dmfe_get_stats;
 	dev->set_multicast_list = &dm9000_hash_table;
-	dev->do_ioctl 		= &dmfe_do_ioctl;

 #if defined(CHECKSUM)
 	dev->features = dev->features | NETIF_F_NO_CSUM;
@@ -382,7 +374,6 @@
 	/* Init driver variable */
 	db->reset_counter 	= 0;
 	db->reset_tx_timeout 	= 0;
-	db->cont_rx_pkt_cnt	= 0;

 	/* check link state and media speed */
 	db->Speed =10;
@@ -404,12 +395,6 @@
 		mdelay(1);
 	}while(i<3000);	/* wait 3 second  */
 	//printk("i=%d  Speed=%d\n",i,db->Speed);
-	/* set and active a timer process */
-	init_timer(&db->timer);
-	db->timer.expires 	= DMFE_TIMER_WUT * 2;
-	db->timer.data 		= (unsigned long)dev;
-	db->timer.function 	= &dmfe_timer;
-	add_timer(&db->timer);	//Move to DM9000 initiallization was
finished.

 	netif_start_queue(dev);

@@ -588,7 +573,6 @@

 	/* Saved the time stamp */
 	dev->trans_start = jiffies;
-	db->cont_rx_pkt_cnt =0;

 	/* Free this SKB */
 	dev_kfree_skb(skb);
@@ -608,9 +592,6 @@
 	board_info_t *db = (board_info_t *)dev->priv;
 	DMFE_DBUG(0, "dmfe_stop", 0);

-	/* deleted timer */
-	del_timer(&db->timer);
-
 	netif_stop_queue(dev);

 	/* free interrupt */
@@ -717,15 +698,8 @@
 	if (int_status & DM9KS_TX_INTR)
 		dmfe_tx_done(0);

-	if (db->cont_rx_pkt_cnt>=CONT_RX_PKT_CNT)
-	{
-		iow(db, DM9KS_IMR, 0xa2);
-	}
-	else
-	{
-		/* Re-enable interrupt mask */
-		iow(db, DM9KS_IMR, DM9KS_REGFF);
-	}
+    /* Re-enable interrupt mask */
+    iow(db, DM9KS_IMR, DM9KS_REGFF);

 	/* Restore previous register address */
 	PUTB(reg_save, db->io_addr);
@@ -746,15 +720,6 @@
 	return &db->stats;
 }

-/*
-  Process the upper socket ioctl command
-*/
-static int dmfe_do_ioctl(struct net_device *dev, struct ifreq *ifr,
int cmd)
-{
-	DMFE_DBUG(0, "dmfe_do_ioctl()", 0);
-	return 0;
-}
-
 /* Our watchdog timed out. Called by the networking layer */
 static void
 dmfe_timeout(struct net_device *dev)
@@ -805,26 +770,6 @@
 	PUTB(reg_save, db->io_addr);

 }
-/*
-  A periodic timer routine
-*/
-static void dmfe_timer(unsigned long data)
-{
-	struct net_device * dev = (struct net_device *)data;
-	board_info_t *db = (board_info_t *)dev->priv;
-	DMFE_DBUG(0, "dmfe_timer()", 0);
-
-	if (db->cont_rx_pkt_cnt>=CONT_RX_PKT_CNT)
-	{
-		db->cont_rx_pkt_cnt=0;
-		iow(db, DM9KS_IMR, DM9KS_REGFF);
-	}
-	/* Set timer again */
-	db->timer.expires = DMFE_TIMER_WUT;
-	add_timer(&db->timer);
-
-	return;
-}

 #if !defined(CHECKSUM)
 #define check_rx_ready(a)	((a) == 0x01)
@@ -975,13 +920,6 @@
 			dev->last_rx=jiffies;
 			db->stats.rx_packets++;
 			db->stats.rx_bytes += rx.desc.length;
-			db->cont_rx_pkt_cnt++;
-
-			if (db->cont_rx_pkt_cnt>=CONT_RX_PKT_CNT)
-			{
-				dmfe_tx_done(0);
-				break;
-			}
 		}

 	}while((rxbyte & 0x01) == DM9KS_PKT_RDY);