The APIC timer setup code synchronizes the local APIC timer to the PIT/HPET. This is pointless as the PIT and the local APIC timer frequency are not correlated and the APIC timer calibration can never be accurate enough to avoid that the local APIC timer and the PIT/HPET drift apart. Simply remove it. Signed-off-by: Thomas Gleixner Signed-off-by: Chris Wright Signed-off-by: Ingo Molnar --- arch/x86_64/kernel/apic.c | 20 -------------------- 1 file changed, 20 deletions(-) Index: linux-2.6.22-rc6-mm/arch/x86_64/kernel/apic.c =================================================================== --- linux-2.6.22-rc6-mm.orig/arch/x86_64/kernel/apic.c 2007-07-15 17:39:44.000000000 +0200 +++ linux-2.6.22-rc6-mm/arch/x86_64/kernel/apic.c 2007-07-15 17:48:58.000000000 +0200 @@ -791,26 +791,6 @@ static void setup_APIC_timer(unsigned in local_irq_save(flags); - /* wait for irq slice */ - if (hpet_address && hpet_use_timer) { - int trigger = hpet_readl(HPET_T0_CMP); - while (hpet_readl(HPET_COUNTER) >= trigger) - /* do nothing */ ; - while (hpet_readl(HPET_COUNTER) < trigger) - /* do nothing */ ; - } else { - int c1, c2; - outb_p(0x00, 0x43); - c2 = inb_p(0x40); - c2 |= inb_p(0x40) << 8; - do { - c1 = c2; - outb_p(0x00, 0x43); - c2 = inb_p(0x40); - c2 |= inb_p(0x40) << 8; - } while (c2 - c1 < 300); - } - irqen = ! cpu_isset(smp_processor_id(), timer_interrupt_broadcast_ipi_mask); __setup_APIC_LVTT(clocks, 0, irqen); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/