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authorThomas Gleixner <tglx@linutronix.de>2007-10-12 23:04:06 +0200
committerThomas Gleixner <tglx@inhelltoy.tec.linutronix.de>2007-10-12 23:04:06 +0200
commit500ff08b76878a45391fffc7a4c972883503050e (patch)
tree7f597708789a036c29930ac04ff638a861d39b61
parent801740971af7c6256b7ad2472706d43ed008fd3d (diff)
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x86_64: remove pit synchronization
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 <tglx@linutronix.de> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
-rw-r--r--arch/x86/kernel/apic_64.c18
1 files changed, 0 insertions, 18 deletions
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index ce2f8015d5ce..a73b443a1236 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -790,24 +790,6 @@ static void setup_APIC_timer(unsigned int clocks)
local_irq_save(flags);
- /* wait for irq slice */
- if (hpet_address && hpet_use_timer) {
- u32 trigger = hpet_readl(HPET_T0_CMP);
- while (hpet_readl(HPET_T0_CMP) == 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);