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>
---
patch-2.6.26-rc1-20080505-timer-8259-6
diff -up --recursive --new-file linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/io_apic_32.c linux-2.6.26-rc1-20080505/arch/x86/kernel/io_apic_32.c
--- linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/io_apic_32.c 2008-05-21 18:52:36.000000000 +0000
+++ linux-2.6.26-rc1-20080505/arch/x86/kernel/io_apic_32.c 2008-05-21 18:52:36.000000000 +0000
@@ -58,6 +58,7 @@ static struct { int pin, apic; } ioapic_
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(vo
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 -up --recursive --new-file linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/io_apic_64.c linux-2.6.26-rc1-20080505/arch/x86/kernel/io_apic_64.c
--- linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/io_apic_64.c 2008-05-18 00:24:43.000000000 +0000
+++ linux-2.6.26-rc1-20080505/arch/x86/kernel/io_apic_64.c 2008-05-18 00:24:43.000000000 +0000
@@ -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(vo
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 -up --recursive --new-file linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/nmi_32.c linux-2.6.26-rc1-20080505/arch/x86/kernel/nmi_32.c
--- linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/nmi_32.c 2008-05-16 20:11:41.000000000 +0000
+++ linux-2.6.26-rc1-20080505/arch/x86/kernel/nmi_32.c 2008-05-21 07:06:45.000000000 +0000
@@ -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 -up --recursive --new-file linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/nmi_64.c linux-2.6.26-rc1-20080505/arch/x86/kernel/nmi_64.c
--- linux-2.6.26-rc1-20080505.macro/arch/x86/kernel/nmi_64.c 2008-05-05 02:55:24.000000000 +0000
+++ linux-2.6.26-rc1-20080505/arch/x86/kernel/nmi_64.c 2008-05-21 07:07:26.000000000 +0000
@@ -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)
diff -up --recursive --new-file linux-2.6.26-rc1-20080505.macro/include/asm-x86/io_apic.h linux-2.6.26-rc1-20080505/include/asm-x86/io_apic.h
--- linux-2.6.26-rc1-20080505.macro/include/asm-x86/io_apic.h 2008-05-05 02:55:57.000000000 +0000
+++ linux-2.6.26-rc1-20080505/include/asm-x86/io_apic.h 2008-05-21 07:04:37.000000000 +0000
@@ -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
--
