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    SubjectRe: spin_lock error in arch/i386/kernel/time.c on APM resume
    On Sat, 12 Mar 2005, George Anzinger wrote:

    > I agree. Still in all that follows, no one has addressed the apparent race
    > described above. The reason the system reported the errors that started this
    > thread is that the APM restore code was trying to read the cmos clock (I
    > assume to set the xtime clock) WHILE the timer interrupt code what trying to
    > set the cmos clock from xtime.

    Doesn't my reply explain the actual problem? The code path being;

    arch/i386/kernel/apm.c
    suspend()
    write_seqlock_irq(xtime_lock)
    ...
    write_sequnlock_irq(xtime_lock)
    <interrupts enabled>
    device_power_up()
    timer_resume()
    get_cmos_time();

    So this covers the problem that the reporter reported, so yes it's setting
    xtime but we shouldn't be taking interrupts in the first place, so i
    posted the patch to cover that. APM was clearly violating PM resume
    procedures.

    Thanks,
    Zwane


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