lkml.org 
[lkml]   [1999]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: linux interrupt handling problem
    From
    Date
    >>>>> "Roman" == Roman Zippel <zippel@fh-brandenburg.de> 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.

    Jes

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:54    [W:0.021 / U:0.248 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site