x86: I/O APIC: clean up the 8259A on a NMI watchdog failure

There is no point in keeping the 8259A enabled if the I/O APIC NMI
watchdog has failed and the 8259A is not used to pass through regular
timer interrupts.  This fixes problems with some systems where some logic
gets confused.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 41218ac..7c7d88e 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -58,6 +58,7 @@
 static DEFINE_SPINLOCK(ioapic_lock);
 static DEFINE_SPINLOCK(vector_lock);
 
+int timer_through_8259 __initdata;
 
 /*
  *	Is the SiS APIC rmw bug present ?
@@ -2194,6 +2195,7 @@
 		enable_8259A_irq(0);
 		if (timer_irq_works()) {
 			printk("works.\n");
+			timer_through_8259 = 1;
 			if (pin1 != -1)
 				replace_pin_at_irq(0, apic1, pin1, apic2, pin2);
 			else