Re: [PATCH][POKE] Skip looking for ioapic overrides when ioapics arenot present

[Ingo Molnar]

* Florian Mickler <florian@xxxxxxxxxxx> wrote:

> From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
> 
> Avinash Kurup <kurup.avinash@xxxxxxxxx> writes:
> 
> > Hi Eric,
> > ÂÂÂ I get the following errors while booting into 2.6.35-rc1. I did not
> > get these in 2.6.34 . The computer however boots and works fine, So its not
> > serious but the following errors are displayed in dmesg.
> >
> > [ÂÂÂ 0.089969] ERROR: Unable to locate IOAPIC for GSI 13
> > [ÂÂÂ 0.090556] ERROR: Unable to locate IOAPIC for GSI 8
> > [ÂÂÂ 0.091104] ERROR: Unable to locate IOAPIC for GSI 12
> > [ÂÂÂ 0.091375] ERROR: Unable to locate IOAPIC for GSI 1
> > [ÂÂÂ 0.093195] ERROR: Unable to locate IOAPIC for GSI 4
> > [ÂÂÂ 0.094342] ERROR: Unable to locate IOAPIC for GSI 10
> > [ÂÂÂ 0.096335] ERROR: Unable to locate IOAPIC for GSI 6
> 
> The new warning originates from acpi_get_override_irq, which I changed to
> use helper functions that warn when they fail.
> 
> When IOAPICs and ACPI are enabled in a kernel and run on ACPI hardware
> that doesn't use the ioapics the pnp acpi code calls this function,
> looking for ACPI irq overrides.  ACPI irq overrides exist only in the
> ioapic case so this function will never succeed.  So make the function
> fail fast so we don't call into help functions that legitimately
> complain when they fail.
> 
> [I submit this as the corresponding bug report is still not closed, the patch 
> not merged, distributions applying this patch, it is tested to work and I found
> nowhere any resoning as to why this should be out of tree. I just guessed on
> the stable tag and number. -Florian] 

The patch does not build when CONFIG_ACPI is disabled:

 arch/x86/kernel/apic/io_apic.c: In function âacpi_get_override_irqâ:
 arch/x86/kernel/apic/io_apic.c:3792:6: error: âacpi_irq_modelâ undeclared (first use in this function)
 arch/x86/kernel/apic/io_apic.c:3792:24: error: âACPI_IRQ_MODEL_IOAPICâ undeclared (first use in this function)

When you or Eric resubmits the fixed patch please use the improved changelog 
below.

Thanks,

	Ingo

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