--- CUT HERE ---
--- linux-2.4.22/arch/i386/kernel/io_apic.c	2003-08-25 21:44:39.000000000 +1000
+++ linux-2.4.22-rd/arch/i386/kernel/io_apic.c	2003-12-22 13:31:32.000000000 +1000
@@ -1612,12 +1612,56 @@ static inline void check_timer(void)
 				check_nmi_watchdog();
 			}
 			return;
 		}
 		clear_IO_APIC_pin(0, pin1);
-		printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC\n");
+		printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC INTIN%d\n",pin1);
+	}
+
+#if defined(CONFIG_ACPI_BOOT) && defined(CONFIG_X86_UP_IOAPIC)
+	/* for nforce2 try vector 0 on pin0
+	 * Note 8259a is already masked, also by default
+	 * the io_apic_set_pci_routing call disables the 8259 irq 0
+	 * so we must be connected directly to the 8254 timer if this works
+	 * Note2: this violates the above comment re Subtle but works!
+	 */
+	printk(KERN_INFO "..TIMER: Is timer irq0 connected to IO-APIC INTIN0? ...\n");
+	if (pin1 != -1) {
+		extern spinlock_t i8259A_lock;
+		unsigned long flags;
+		int tok, saved_timer_ack = timer_ack;
+		/*
+		 * Ok, does IRQ0 through the IOAPIC work?
+		 */
+		io_apic_set_pci_routing ( 0, 0, 0, 0, 0); /* connect pin */
+		unmask_IO_APIC_irq(0);
+		timer_ack = 0;
+
+		/*
+		 * Ok, does IRQ0 through the IOAPIC work?
+		 */
+		spin_lock_irqsave(&i8259A_lock, flags);
+		Dprintk("..TIMER 8259A ints disabled?, imr1:%02x, imr2:%02x\n", inb(0x21), inb(0xA1));
+		tok = timer_irq_works();
+		spin_unlock_irqrestore(&i8259A_lock, flags);
+		if (tok) {
+			if (nmi_watchdog == NMI_IO_APIC) {
+				disable_8259A_irq(0);
+				setup_nmi();
+				enable_8259A_irq(0);
+				check_nmi_watchdog();
+			}
+			printk(KERN_INFO "..TIMER: works OK on IO-APIC INTIN0 irq0\n" );
+			return;
+		}
+		/* failed */
+		timer_ack = saved_timer_ack;
+		clear_IO_APIC_pin(0, 0);
+		io_apic_set_pci_routing ( 0, pin1, 0, 0, 0);
+		printk(KERN_ERR "..MP-BIOS: 8254 timer not connected to IO-APIC INTIN0\n");
 	}
+#endif
 
 	printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
 	if (pin2 != -1) {
 		printk("\n..... (found pin %d) ...", pin2);
 		/*
--- CUT HERE ---