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Commit 3dfbc884 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Thomas Gleixner
Browse files

x86: C1E late detection fix. Really switch off lapic timer 



Doh, I completely missed that devices marked DUMMY are not running
the set_mode function. So we force broadcasting, but we keep the
local APIC timer running.

Let the clock event layer mark the device _after_ switching it off.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e6d5a11d

arch/x86/kernel/apic_64.c

+0 −3
Original line number Diff line number Diff line
@@ -974,15 +974,12 @@ void __init setup_boot_APIC_clock (void) 
 */

void __cpuinit check_boot_apic_timer_broadcast(void)

{

	struct clock_event_device *levt = &per_cpu(lapic_events, boot_cpu_id);



	if (!disable_apic_timer ||

	    (lapic_clockevent.features & CLOCK_EVT_FEAT_DUMMY))

		return;



	printk(KERN_INFO "AMD C1E detected late. Force timer broadcast.\n");

	lapic_clockevent.features |= CLOCK_EVT_FEAT_DUMMY;

	levt->features |= CLOCK_EVT_FEAT_DUMMY;



	local_irq_enable();

	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE, &boot_cpu_id);

kernel/time/tick-broadcast.c

+4 −14
Original line number Diff line number Diff line
@@ -222,20 +222,8 @@ static void tick_do_broadcast_on_off(void *why) 
	if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP))

		goto out;



	/*

	 * Defect device ?

	 */

	if (!tick_device_is_functional(dev)) {

		/*

		 * AMD C1E wreckage fixup:

		 *

		 * Device was registered functional in the first

		 * place. Now the secondary CPU detected the C1E

		 * misfeature and notifies us to fix it up

		 */

		if (*reason != CLOCK_EVT_NOTIFY_BROADCAST_FORCE)

	if (!tick_device_is_functional(dev))

		goto out;

	}



	switch (*reason) {

	case CLOCK_EVT_NOTIFY_BROADCAST_ON:
@@ -246,6 +234,8 @@ static void tick_do_broadcast_on_off(void *why) 
				clockevents_set_mode(dev,

						     CLOCK_EVT_MODE_SHUTDOWN);

		}

		if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)

			dev->features |= CLOCK_EVT_FEAT_DUMMY;

		break;

	case CLOCK_EVT_NOTIFY_BROADCAST_OFF:

		if (cpu_isset(cpu, tick_broadcast_mask)) {