[Techtalk] Spurious kernel interrupt?
Alain Tesio
alain at onesite.org
Thu Aug 29 23:04:57 EST 2002
On Thu, 29 Aug 2002 16:39:08 -0400
Terri Oda <terri at zone12.com> wrote:
>
> Aug 29 16:25:09 ostraya kernel: spurious 8259A interrupt: IRQ7.
In the kernel sources, file /arch/i386/kernel/i8259.c, it's described
as "hardware problems".
The conditional defines CONFIG_SMP and CONFIG_X86_LOCAL_APIC
are used in this file, maybe you have a kernel configured for SMP and a
system with only one processor ?
Alain
spin_lock_irqsave(&i8259A_lock, flags);
/*
* Lightweight spurious IRQ detection. We do not want
* to overdo spurious IRQ handling - it's usually a sign
* of hardware problems, so we only do the checks we can
* do without slowing down good hardware unnecesserily.
*
* Note that IRQ7 and IRQ15 (the two spurious IRQs
* usually resulting from the 8259A-1|2 PICs) occur
* even if the IRQ is masked in the 8259A. Thus we
* can check spurious 8259A IRQs without doing the
* quite slow i8259A_irq_real() call for every IRQ.
* This does not cover 100% of spurious interrupts,
* but should be enough to warn the user that there
* is something bad going on ...
*/
if (cached_irq_mask & irqmask)
goto spurious_8259A_irq;
cached_irq_mask |= irqmask;
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