x86: apic reset counter on shutdown

Impact: avoid spurious lapic timer events on shutdown

The apic timer might be close to firing when it is shutdown. We can
not really disable the timer - we just mask the interrupt. That way we
can get an extra interrupt when it is reenabled. Set the counter to
max on shutdown to avoid this.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic.c

@@ -441,6 +441,7 @@ static void lapic_timer_setup(enum clock_event_mode mode,
 		v = apic_read(APIC_LVTT);
 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
 		apic_write(APIC_LVTT, v);
+		apic_write(APIC_TMICT, 0xffffffff);
 		break;
 	case CLOCK_EVT_MODE_RESUME:
 		/* Nothing to do here */