[PATCH] acpi: mcfg: Set MCFGMMIONotReserved error to low

[Alex Hung]

On 10/25/2012 04:48 PM, Colin Ian King wrote:
> On 25/10/12 06:42, Alex Hung wrote:
>> In PCI Firmware Specification, it claims "If the operating system does
>> not natively
>> comprehend reserving the MMCFG region, the MMCFG region must be
>> reserved by firmware."
>> However, Linux is an operating system that comprehend MMCFG, and
>> therefore it is not
>> a problem for not declaring it.
>>
>> Signed-off-by: Alex Hung <alex.hung at canonical.com>
>> ---
>>   src/acpi/mcfg/mcfg.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/src/acpi/mcfg/mcfg.c b/src/acpi/mcfg/mcfg.c
>> index 9dfd9fd..878c0f1 100644
>> --- a/src/acpi/mcfg/mcfg.c
>> +++ b/src/acpi/mcfg/mcfg.c
>> @@ -200,7 +200,7 @@ static int mcfg_test1(fwts_framework *fw)
>>           if ((memory_map_list != NULL) &&
>>               (!fwts_memory_map_is_reserved(memory_map_list,
>> config->base_address))) {
>>
>> -            fwts_failed(fw, LOG_LEVEL_MEDIUM, "MCFGMMIONotReserved",
>> +            fwts_failed(fw, LOG_LEVEL_LOW, "MCFGMMIONotReserved",
>>                   "MCFG mmio config space at 0x%" PRIx64
>>                   " is not reserved in the memory map table",
>>                   config->base_address);
>>
>
> I'm not 100% sure how significant this is.  Can you take a look at what
> the kernel does if it isn't reserved by firmware?  I think the relevant
> code is in arch/x86/pci/*
>
> Personally I don't mind dropping this to LOW, but I'd like to know what
> the kernel does nowadays for this issue.
>
> Colin
>
>

Hi Colin,

Thanks for reminding.

I checked mmconfig-shared.c and there is a function 
"pci_mmconfig_insert" to insert (reserve) the memory address in MCFG. It 
seems safe to lower the error level.

Cheers,
Alex Hung