- /* 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.
- */
- raw_spin_lock(&i8259A_lock);
- outb(0x0c, PIC_MASTER_OCW3);
- /* Ack the IRQ; AEOI will end it automatically. */
- inb(PIC_MASTER_POLL);
- raw_spin_unlock(&i8259A_lock);
- }
-