Bug reports requested - acpi

Nate Lawson nate at root.org
Tue Sep 7 11:26:56 PDT 2004

Roman Kurakin wrote:
> Nate Lawson wrote:
>> Roman Kurakin wrote:
>>> Nate Lawson:
>>>> set hint.apic.0.disabled="1" at the loader prompt 
>>> I'll try this tomorrow since I am going to sleep now. I hope it will 
>>> reboot.
>>> If not I'll try to get to the work to fix its state.
>> I have not heard back from you about whether disabling the APIC (not 
>> ACPI) alone fixes the problem.
> My answer was:
>    I was unaware of all that safe mode turns off, and than I last time 
> check this I ovelooked
>    that apic is also disabled. It seems that problem with APIC.
>    But could you tell me how changes in ACPICA affect APIC code?
> Sorry if it was not very clean. Yes, disabling apic helps.

Please answer yes or no:  ACPI enabled but APIC disabled works 100%? 
Safe mode disables both ACPI and APIC so it's not a good test of where 
the problem is.  You should probably also test with ACPI disabled but 
APIC enabled ("set hint.acpi.0.disabled=1").

The APIC code has two methods of enumerating PIC devices:  ACPI and MP 
table.  With ACPI enabled, the APIC code gets its info from the MADT 
table.  With ACPI disabled, it uses the MP table.  Many older (< 2001) 
systems have problems with their MADT but an ok MP table.  I think there 
are a few systems that have a correct MADT but flawed MP table but that 
is rare.


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