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    SubjectRe: linux interrupt handling problem
    >>>>> "Roman" == Roman Zippel <> writes:

    Roman> The ppc has a different interrupt architecture, it has only a
    Roman> single interrupt entry and a single interrupt priority
    Roman> (on/off). In that file there is also a mask_and_ack_irq(irq)
    Roman> _before_ that loop. The m68k cpu is completly different here,
    Roman> it has multiple entries and multiple priorities (0-7) and the
    Roman> acknowledgement needs sometimes also to be done within that
    Roman> loop by the driver, so it doesn't work anymore. The
    Roman> requirement for a sti() in interrupts makes it impossible to
    Roman> utilize these priorities to achieve better interrupt
    Roman> perfomance. What other people sometimes would like to have -
    Roman> the ability to preempt slow interrupts - get we for free
    Roman> implemented in hardware, but we can't use it because of the
    Roman> above requirement. :(

    We already have this feature, you run the critical interrupt as
    SA_INTERRUPT, the rest as normal sti() ones. The 7 priorities don't
    buy you anything.


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