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    SubjectRe: APIC, changing level/edge interrupt
    Tim Hockin wrote:

    >Of course. My point was that if it does not, it's a bug in the BIOS.
    >
    >
    >
    Something Windows doesn't seem to be affected by so I don't think we'll
    get much help fixing the bios.

    >>But since BIOS can configure the APIC then the kernel should be able to
    >>
    >>
    >
    >Of course, but the kernel has no way to know whether a device should be
    >edge or level triggered unless you have a driver for that device. And
    >even if you do, I don't know that there is an API in kernel to say
    >set_irq_mode(IRQ_EDGE) (though there could be).
    >
    >
    >
    There are some calls in the ACPI layer which plays with the level/edge
    stuff but they don't seem very generic. Besides, what I want right now
    is just some possibility of confirming that this level/edge business is
    the cause of all these problems.

    >>What is the default mode and what does the XT-PIC expect? (it works fine
    >>with the apic disabled).
    >>
    >>
    >
    >I think default is PIC-compatible which is edge by default. I think. I
    >don;t have the book here.
    >
    >
    >
    Ok. The default from the device is level mode which works fine on PIC
    systems. I'm not sure that the hardware actually respects this bit
    because level/pulse mode doesn't make any difference on either PIC or
    APIC systems.

    Rgds
    Pierre

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