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 23:48:30.000000000 -0500
@@ -1089,6 +1089,37 @@
 	 */
 	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
+                /* delay only if required */
+                while( apic_read(APIC_TMCCT) > safecnt )
+                        ndelay(100);
+        }
+#endif
+
 	/*
 	 * NOTE! We'd better ACK the irq immediately,
 	 * because timer handling can be slow.