Re: APEI: Can not request iomem region for GARs

Huang Ying
2011-08-22T05:43:46Z

On 08/20/2011 05:48 AM, Bjorn Helgaas wrote:
> On Tue, Aug 16, 2011 at 9:43 PM, Pavel Ivanov <paivanof@gmail.com> wrote:
>> Ever since I switched from kernel 2.6.38 to 3.0 and later versions I
>> always get the following error message on each boot:
>>
>> [ 2.844242] APEI: Can not request iomem region
>> <00000000bf7b522a-00000000bf7b522c> for GARs.
>>
>> If it was only in dmesg I wouldn't even notice it. But it's always
>> printed on the console which is kind of annoying.
>> I don't quite understand what this message is about and couldn't find
>> anything on the internet. Does this message mean some error that I
>> could fix? If no, is there any way I can suppress it (besides lowering
>> the error level of messages printed on console, of course)?
>
> [+cc Huang Ying, APEI author]
>
> BIOS-e820: 00000000bf79e000 - 00000000bf7d0000 (ACPI NVS)
> APEI: Can not request iomem region <00000000bf7b522a-00000000bf7b522c> for GARs.
>
> This register is in the ACPI NVS region, which is type E820_NVS (not
> E820_RESERVED), so e820_reserve_resources() reserves it as
> IORESOURCE_BUSY. My guess is that Huang tested this on machines where
> the EINJ/ERST registers are in "reserved" regions, not ACPI NVS
> regions. The "reserved" regions are not marked IORESOURCE_BUSY.
>
> Huang, when you fix this, please include something like the following
> (mangled) patch so the error message is more consistent with other
> resource messages.

The patch looks good. Can you resubmit it with changelog?

> Could you also remove the ERST/EINJ/HEST "Table is not found"
> messages? As far as I can tell, these tables are optional, and
> printing the message is confusing to users, e.g.,
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/599715

Yes. This seems confusing to them. I will change this.

Best Regards,
Huang Ying