RE: spurious 8259A interrupt

From: Guennadi Liakhovetski (g.liakhovetski_at_gmx.de)
Date: 03/23/04

  • Next message: Russell King: "Re: OSS: cleanup or throw away" 
    Date:	Tue, 23 Mar 2004 00:09:16 +0100 (CET)
To: "Richard B. Johnson" <root@chaos.analogic.com>

    On Mon, 22 Mar 2004, Richard B. Johnson wrote:

    > On Mon, 22 Mar 2004, Guennadi Liakhovetski wrote:
    >
    > > CPU0 (2nd shot)
    > > 0: 36557 37638 +1081 XT-PIC timer
    > > 1: 59 65 +6 XT-PIC i8042
    > > 2: 0 0 XT-PIC cascade
    > > 5: 0 0 XT-PIC VIA686A
    > > 8: 3 3 XT-PIC rtc
    > > 9: 0 0 XT-PIC acpi, uhci_hcd, uhci_hcd
    > > 10: 0 0 XT-PIC eth0
    > > 12: 84 84 XT-PIC i8042
    > > 14: 1910 1918 +8 XT-PIC ide0
    > > 15: 1 1 XT-PIC ide1
    > > NMI: 18 18
    > > LOC: 36460 37541 +1081
    > > ERR: 36 57 +21
    >
    > First, you are using the 8259A (XT-PIC). This means you have
    > IO-APIC turned off (or it doesn't exist).

    I know. I never said there was one. I said, that the local APIC is used
    for timer interupts - at least, this is how I interpret

    Using local APIC timer interrupts.
    calibrating APIC timer ...

    Am I missing anything trivial?

    > > ide0 + i8042 (keyboard) = 14, whereas errors increased by 21. So, if you
    > > are right, than Alan's wrong (or my understanding of his statement), and
    > > those spurious interrupts occur not only after real ones, or, one real
    > > interrupt can produce several spurious ones.
    >
    > Neither. They are not related. As previously stated, a spurious
    > interrupt occurs when the CPU INT line becomes active, but no
    > interrupt controller caused it to happen. It's just that simple.

    Yes, I saw this your explanation. Thanks again. But, I am not getting
    those errors with local APIC disabled. That's why I thought "local APIC ->
    timer -> spurious interrupts." Maybe I am wrong. But I also can't see how
    enabling the lapic can cause, e.g., power supply glitches to become
    visible. I would be happy and grateful to hear an explanation.

    Thanks
    Guennadi 

    ---
Guennadi Liakhovetski
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  • Next message: Russell King: "Re: OSS: cleanup or throw away"

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