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>

1 files changed, 9 insertions, 2 deletions

diff --git a/arch/x86/kernel/nmi_64.c b/arch/x86/kernel/nmi_64.c
index 5a29ded994fa..0060e44e8989 100644
--- a/arch/x86/kernel/nmi_64.c
+++ b/arch/x86/kernel/nmi_64.c
@@ -21,6 +21,8 @@
 #include <linux/cpumask.h>
 #include <linux/kdebug.h>
 
+#include <asm/i8259.h>
+#include <asm/io_apic.h>
 #include <asm/smp.h>
 #include <asm/nmi.h>
 #include <asm/proto.h>
@@ -90,7 +92,7 @@ int __init check_nmi_watchdog(void)
 
         prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
         if (!prev_nmi_count)
-                return -1;
+                goto error;
 
         printk(KERN_INFO "Testing NMI watchdog ... ");
 
@@ -121,7 +123,7 @@ int __init check_nmi_watchdog(void)
         if (!atomic_read(&nmi_active)) {
                 kfree(prev_nmi_count);
                 atomic_set(&nmi_active, -1);
-                return -1;
+                goto error;
         }
         printk("OK.\n");
 
@@ -132,6 +134,11 @@ int __init check_nmi_watchdog(void)
 
         kfree(prev_nmi_count);
         return 0;
+error:
+        if (nmi_watchdog == NMI_IO_APIC && !timer_through_8259)
+                disable_8259A_irq(0);
+
+        return -1;
 }
 
 static int __init setup_nmi_watchdog(char *str)