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>

4 files changed, 17 insertions, 2 deletions

diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 41218ac75d1..7c7d88ebb96 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -58,6 +58,7 @@ static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 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 @@ static inline void __init check_timer(void)
                 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
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index aa45a85c4d1..2a60bfb7446 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -90,6 +90,7 @@ static int no_timer_check;
 
 static int disable_timer_pin_1 __initdata;
 
+int timer_through_8259 __initdata;
 
 /* Where if anywhere is the i8259 connect in external int mode */
 static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
@@ -1700,6 +1701,7 @@ static inline void __init check_timer(void)
                 enable_8259A_irq(0);
                 if (timer_irq_works()) {
                         apic_printk(APIC_VERBOSE," works.\n");
+                        timer_through_8259 = 1;
                         nmi_watchdog_default();
                         if (nmi_watchdog == NMI_IO_APIC) {
                                 disable_8259A_irq(0);
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
index d322901c38e..6580dae4627 100644
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi_32.c
@@ -24,6 +24,8 @@
 #include <linux/kdebug.h>
 #include <linux/slab.h>
 
+#include <asm/i8259.h>
+#include <asm/io_apic.h>
 #include <asm/smp.h>
 #include <asm/nmi.h>
 #include <asm/timer.h>
@@ -131,6 +133,8 @@ 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);
         timer_ack = 0;
 
         return -1;
diff --git a/arch/x86/kernel/nmi_64.c b/arch/x86/kernel/nmi_64.c
index 5a29ded994f..0060e44e898 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)