Re: APM shutdown oops (Re: [stable] [patch 09/12] Fix SMP poweroff hangs)

[Adrian Bunk <bunk@kernel.org>]

On Thu, Oct 11, 2007 at 02:42:01PM -0400, Jeff Garzik wrote:
> Linus Torvalds wrote:
>> On Wed, 10 Oct 2007, Kevin wrote:
>>> The last kernel I used was 6.2.22 the "dmesg" the file is attached:
>>>
>>> dmesg 2.6.22 line 158 >  apm: overridden by ACPI.
>>>
>>> dmesg, APM on, has no line > apm: overridden by ACPI.
>> Ok, this is the real reason. The APM code does:
>>         if (PM_IS_ACTIVE()) {
>>                 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
>>                 apm_info.disabled = 1;
>>                 return -ENODEV;
>>         }
>> and in previous kernels that would notice that you have ACPI enabled, and 
>> APM gets shut out, and you never see your buggy APM BIOS.
>> In 2.6.23, this apparently doesn't happen for some reason.
>> And I think I see the problem: it's a config change. You don't have 
>> PM_LEGACY enabled. Your config file diff shows:
>> 	-CONFIG_PM_LEGACY=y
>> 	+# CONFIG_PM_LEGACY is not set
>> I suspect we should make CONFIG_APM either depend on, or select, 
>> PM_LEGACY. But as far as I can see, nothing has actually changed in this 
>> area in the kernel, and this bug has been there before - just your config 
>> change made it appear. Rafael? Stephen? Opinions? I'd think that making 
>> APM depend on CONFIG_PM_LEGACY is the right thing to do these days..
>
> Speaking as the author of
>
> 	[PATCH] move pm_register/etc. to CONFIG_PM_LEGACY, pm_legacy.h
>
> I agree.  arch/i386/kernel/apm.c clearly requires include/linux/pm_legacy.h 
> and the legacy PM API.
>
> I would vote for a dependency rather than select, but don't have any strong 
> feelings on the matter...

It should be a select since a dependency would make it needlessly hard 
for kconfig users to find the APM option.

> 	Jeff

cu
Adrian

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