diff options
Diffstat (limited to 'arch/x86/kernel/time_64.c')
| -rw-r--r-- | arch/x86/kernel/time_64.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c index 45914f8844a7..35e0a925da56 100644 --- a/arch/x86/kernel/time_64.c +++ b/arch/x86/kernel/time_64.c @@ -51,6 +51,20 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) { inc_irq_stat(irq0_irqs); + /* Optimized out for !IO_APIC and x86_64 */ + if (timer_ack) { + /* + * Subtle, when I/O APICs are used we have to ack timer IRQ + * manually to deassert NMI lines for the watchdog if run + * on an 82489DX-based system. + */ + spin_lock(&i8259A_lock); + outb(0x0c, PIC_MASTER_OCW3); + /* Ack the IRQ; AEOI will end it automatically. */ + inb(PIC_MASTER_POLL); + spin_unlock(&i8259A_lock); + } + global_clock_event->event_handler(global_clock_event); #ifdef CONFIG_MCA |