Re: acpi resume related patch

on 25/01/2013 15:51 John Baldwin said the following:
> On Friday, January 25, 2013 3:43:33 am Andriy Gapon wrote:
>>
>> If you have ACPI suspend/resume working, if it used to work but stopped working
>> at some time, if it never worked, but you are still hoping, could you please
>> test the following patch and report back?
>>
>> http://svn.freebsd.by/files/acpi-apic-wakeup-final.patch
> 
> This will break systems not using the local APIC since you unconditionally
> call lapic_setup() on resume.This was part of the feature of the previous
> code that by using a dummy pic it could register it only when the local APIC
> was used.

Thank you for drawing my attention to this.  I will try to fix this issue.
The reason I want to remove lapic from 'pics' (and I already described it in a
private email) is that Local APIC is a special kind of PIC.  It's already
explicitly initialized by APs.  Putting it into 'pics' tailq just obfuscates the code.

> It should also be registered before any of the I/O APICs are by
> the design of the local_apic.c code.

In fact, as I see in the code, Local APIC is always registered _after_ I/O APICs.
And thus lapic_resume was called after ioapic_resume.
Additionally, currently there is no synchronization between initialization of
Local APICs on APs and initialization of I/O APICs at the wakeup/resume time.

-- 
Andriy Gapon