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    Subject[patch] clockevents: drivers for i386, fix #2

    * Ingo Molnar <mingo@elte.hu> wrote:

    > yeah, i suspect it works again if you disable:
    >
    > CONFIG_X86_UP_APIC=y
    > CONFIG_X86_UP_IOAPIC=y
    > CONFIG_X86_LOCAL_APIC=y
    > CONFIG_X86_IO_APIC=y
    >
    > as the slowdown has the feeling of a runaway lapic timer irq.
    >
    > from code review so far we can only see an udelay(10) difference in
    > the initialization sequence of the PIT - we'll send a fix for that but
    > i dont think that's the cause of the bug.

    the patch below fixes that particular bug. But ... the symptoms you are
    describing have the feeling of being apic related.

    Ingo

    -------------------->
    Subject: clockevents: drivers for i386, fix #2
    From: Ingo Molnar <mingo@elte.hu>

    add back a mistakenly removed udelay(10) to the PIT initialization
    sequence.

    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    ---
    arch/i386/kernel/i8253.c | 1 +
    1 file changed, 1 insertion(+)

    Index: linux/arch/i386/kernel/i8253.c
    ===================================================================
    --- linux.orig/arch/i386/kernel/i8253.c
    +++ linux/arch/i386/kernel/i8253.c
    @@ -45,6 +45,7 @@ static void init_pit_timer(enum clock_ev
    outb_p(0x34, PIT_MODE);
    udelay(10);
    outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
    + udelay(10);
    outb(LATCH >> 8 , PIT_CH0); /* MSB */
    break;

    -
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