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, 4 insertions, 0 deletions

diff --git a/include/asm-x86/io_apic.h b/include/asm-x86/io_apic.h
index d593e14f0341..a6732566ad05 100644
--- a/include/asm-x86/io_apic.h
+++ b/include/asm-x86/io_apic.h
@@ -137,6 +137,9 @@ extern int sis_apic_bug;
 /* 1 if "noapic" boot option passed */
 extern int skip_ioapic_setup;
 
+/* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */
+extern int timer_through_8259;
+
 static inline void disable_ioapic_setup(void)
 {
         skip_ioapic_setup = 1;
@@ -162,6 +165,7 @@ extern void ioapic_init_mappings(void);
 
 #else  /* !CONFIG_X86_IO_APIC */
 #define io_apic_assign_pci_irqs 0
+static const int timer_through_8259 = 0;
 #endif
 
 #endif