Re: [PATCH] x86/ioapic: Ignore root bridges without a companion ACPI device

[Borislav Petkov]

On Sat, Sep 10, 2016 at 11:40:45PM +0800, Rui Wang wrote:
> Some PCI root bridges don't have a corresponding ACPI device.
> This can be the case on some old platforms. Don't call acpi_ioapic_add()
> on these bridges because they can't support ioapic hotplug.
> 
> v2: Per Boris's review, removed the unnecessary local var; refined comment
> 
> Signed-off-by: Rui Wang <rui.y.wang@xxxxxxxxx>
> Reviewed-by: Borislav Petkov <bp@xxxxxxxxx>
>
> ---
>  drivers/pci/setup-bus.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index ec538d3..8b4e231 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -1855,7 +1855,10 @@ void __init pci_assign_unassigned_resources(void)
>  
>  	list_for_each_entry(root_bus, &pci_root_buses, node) {
>  		pci_assign_unassigned_root_bus_resources(root_bus);
> -		acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
> +
> +		/* make sure the root bridge has a companion ACPI device */
> +		if (ACPI_HANDLE(root_bus->bridge))
> +			acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));

Reported-and-tested-by: Borislav Petkov <bp@xxxxxxx>

Thanks Rui!

-- 
Regards/Gruss,
    Boris.

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