diff -urN linux-2.6.0-test11/arch/i386/kernel/apic.c linux-2.6.0-test11-nf2/arch/i386/kernel/apic.c
--- linux-2.6.0-test11/arch/i386/kernel/apic.c	2003-11-26 15:46:07.000000000 -0500
+++ linux-2.6.0-test11-nf2/arch/i386/kernel/apic.c	2003-12-13 15:04:38.000000000 -0500
@@ -1089,6 +1089,32 @@
 	 */
 	irq_stat[cpu].apic_timer_irqs++;
 
+#ifdef CONFIG_MK7 && CONFIG_BLK_DEV_AMD74XX
+	/*
+	 * on 2200XP & nforce2 chipset we need 600ns?
+	 * from timer irq start to apic irq ack to prevent
+	 * hard lockups, use apic timer itself.
+	 * C1 disconnect bit related.  Ross Dickson.
+	 */
+	{
+	  static unsigned int passno, safecnt;
+	  if(!passno {/*calculate timing*/
+	    safecnt = apic_read(APIC_TMICT) -
+	      ( (600UL * apic_read(APIC_TMICT) ) /
+		(1000000000UL/HZ) );
+	    printk("..APIC TIMER ack delay, reload:%u, safe:%u\n",
+		   apic_read(APIC_TMICT), safecnt);
+	    passno++;
+	  }
+#if APIC_DEBUG
+	     if(passno<12) {
+	       unsigned int at1 = apic_read(APIC_TMCCT);
+	       if(passno>1)
+		 Dprintk("..APIC TIMER ack delay, predelay count: %u \n", at1 );
+	       passno++;
+	     }
+#endif
+
 	/*
 	 * NOTE! We'd better ACK the irq immediately,
 	 * because timer handling can be slow.