common_interrupt: No irq handler for vector

From: Shuah Khan
Date: Fri Dec 11 2020 - 15:44:00 EST


I am debugging __common_interrupt: 1.55 No irq handler for vector
messages and noticed comments and code don't agree:

arch/x86/kernel/apic/msi.c: msi_set_affinity() says:


* If the vector is in use then the installed device handler will
* denote it as spurious which is no harm as this is a rare event
* and interrupt handlers have to cope with spurious interrupts
* anyway. If the vector is unused, then it is marked so it won't
* trigger the 'No irq handler for vector' warning in
* common_interrupt().

common_interrupt() prints message if vector is unused: VECTOR_UNUSED

ack_APIC_irq();

if (desc == VECTOR_UNUSED) {
pr_emerg_ratelimited("%s: %d.%u No irq handler for vector\n",
__func__, smp_processor_id(), vector);
}

Something wrong here?

thanks,
-- Shuah