Re: [PATCH 4/8] ACPI, APEI, Resolve false conflict between ACPI NVSand APEI

[Huang Ying]

On 09/20/2011 10:09 AM, Bjorn Helgaas wrote:
> On Mon, Sep 19, 2011 at 7:38 PM, Huang Ying <ying.huang@xxxxxxxxx> wrote:
>> Some firmware will access memory in ACPI NVS region via APEI.  That
>> is, instructions in APEI ERST/EINJ table will read/write ACPI NVS
>> region.  The original resource conflict checking in APEI code will
>> check memory/ioport accessed by APEI via general resource management
>> mech.  But ACPI NVS region is marked as busy already, so that the
>> false resource conflict will prevent APEI ERST/EINJ to work.
>>
>> To fix this, this patch excludes ACPI NVS regions when APEI components
>> request resources.  So that they will not conflict with ACPI NVS
>> regions.
> 
> I think this is much, much too complicated.
> 
> Yinghai's three-line e820.c patch to leave ACPI NVS regions in the
> iomem_resource tree, but as not busy, is far better.

ACPI NVS should only be used by firmware or firmware interpreter instead
of the ordinary drivers.  So I think that is reasonable to make it busy
in iomem resource tree.

Best Regards,
Huang Ying
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