From 33c053d0aec344c8b2ad6966d904ebeff64e590b Mon Sep 17 00:00:00 2001
From: Glauber Costa <gcosta@redhat.com>
Date: Mon, 21 Jul 2008 18:42:52 -0300
Subject: [PATCH] x86: wrap MCA_bus test around an ifdef

Only test for MCA_bus if support for MCA is compiled in.
Also, for x86_64, write the code inside the conditional
for consistency with i386. It won't bite us, since it'll
probably never select CONFIG_MCA anyway.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/time_32.c | 2 ++
 arch/x86/kernel/time_64.c | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/arch/x86/kernel/time_32.c b/arch/x86/kernel/time_32.c
index 7215bc6adfcc..77b400f06ea2 100644
--- a/arch/x86/kernel/time_32.c
+++ b/arch/x86/kernel/time_32.c
@@ -94,6 +94,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
 
 	do_timer_interrupt_hook();
 
+#ifdef CONFIG_MCA
 	if (MCA_bus) {
 		/* The PS/2 uses level-triggered interrupts.  You can't
 		turn them off, nor would you want to (any attempt to
@@ -107,6 +108,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
 		u8 irq_v = inb_p( 0x61 );	/* read the current state */
 		outb_p( irq_v|0x80, 0x61 );	/* reset the IRQ */
 	}
+#endif
 
 	return IRQ_HANDLED;
 }
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
index 2be67c24909e..207a7a1d7ac5 100644
--- a/arch/x86/kernel/time_64.c
+++ b/arch/x86/kernel/time_64.c
@@ -16,6 +16,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/time.h>
+#include <linux/mca.h>
 
 #include <asm/i8253.h>
 #include <asm/hpet.h>
@@ -54,6 +55,13 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
 
 	global_clock_event->event_handler(global_clock_event);
 
+#ifdef CONFIG_MCA
+	if (MCA_bus) {
+		u8 irq_v = inb_p(0x61);       /* read the current state */
+		outb_p(irq_v|0x80, 0x61);     /* reset the IRQ */
+	}
+#endif
+
 	return IRQ_HANDLED;
 }