Re: WARNING: at arch/x86/kernel/apic/apic.c:249 native_apic_write_dummy

[Vegard Nossum <vegard.nossum@gmail.com>]

2009/6/17 Cyrill Gorcunov <gorcunov@gmail.com>:
> Vegard, could you test the patch?
>
>        -- Cyrill
> ---
>
> If we have apic disabled we don't even switch to APIC mode and do not
> calling for connect_bsp_APIC. Though on SMP compiled kernel the
> native_machine_shutdown does try to write the apic register anyway.
> Fix it with explicit check if we really should touch apic registers.
>
> Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> ---
>  arch/x86/kernel/apic/io_apic.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> Index: linux-2.6.git/arch/x86/kernel/apic/io_apic.c
> =====================================================================
> --- linux-2.6.git.orig/arch/x86/kernel/apic/io_apic.c
> +++ linux-2.6.git/arch/x86/kernel/apic/io_apic.c
> @@ -2003,7 +2003,9 @@ void disable_IO_APIC(void)
>        /*
>         * Use virtual wire A mode when interrupt remapping is enabled.
>         */
> -       disconnect_bsp_APIC(!intr_remapping_enabled && ioapic_i8259.pin != -1);
> +       if (cpu_has_apic)
> +               disconnect_bsp_APIC(!intr_remapping_enabled &&
> +                               ioapic_i8259.pin != -1);
>  }
>
>  #ifdef CONFIG_X86_32
>

Seems to work here:

[  317.596743] ACPI: Preparing to enter system sleep state S5
[  317.633421] Disabling non-boot CPUs ...
[  317.637493] Power down.
[  317.638305] acpi_power_off called

and no warning.

Thanks!


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036