Hi,

From: Vincent <10.50@free.fr>
Subject: Re: ACPI-CA v. 20050309
Date: Wed, 23 Mar 2005 11:18:32 +0100

> Konishiwa ! ;)

This should be "kon-nichiwa"(hello) :)

> > Vincent, could you narrow down more _where_ the reboot happens
> > in ACPI-CA code?  If it happens _only_ on your laptop in the world,
> > it's ok, but if not, there should be a fix for 2.0 and 3.0, not only
> > for -current.  Importing a newer ACPI-CA for 2.0 or 3.0 is not
> > a good idea.
> 
> I have no idea whether it happens only on my laptop or not. I guess it 
> is somehow related to event report. As long as the code does not call 
> the _BST control method, all is fine. When it calls it, the method 
> returns OK with the valid infos. Then, suddently, a short while after, 
> the whole system reboots - as if the call had somehow altered the event 
> handler and made it point nowhere. There is no crash, no panic, nothing, 
> just a plain and mere reboot.

Hmm, the reboot is asynchronous to the evaluation of _BST.
Can I interpret 'reboot' as 'immediate hardware reset' (just confirming)?
Without any trace or crash dump, it's very hard to track down,
and it's even worse for remote debugging!

> Could be related to sysmon, too. Or to interrupt handling.
> 
> I accept that importing a new ACPICA version for 2.0 is useless. But I 
> don't see your point for 3.0. When 3.0 is supposed to be derived from 
> current?

3.0 is already branched from -current, and it's too late to make a
big change like replacing ACPI CA.  But maybe we can maintain a
separate patch for 2.0/3.0 (update to the latest ACPI CA, for people
suffering from bugs).

> > I hate the idea of just upgrading the ACPI-CA to fix some of problems.
> > In my past experience, a newer ACPI-CA is not always better than older ones.
> > The newer one surely has some bug fixes, but also has some
> > enhancements/cleanups, which means it may include some new bugs
> > or errors.  So if it fixes _your_ problem, it may make _others_ not
> > working.  Don't treat ACPI-CA as a black box, just replacing it will
> > not make everyone happy (especially makes the developers handle many PR's :)
> 
> I see your point. Of course, my point of view is egoistic. Well, it was 
> something like: "Since it seems nothing has changed between 2.99.12 and 
> 2.99.13, it might be a 'resident' bug in the Acpica code, so, instead of 
> looking into a foreign code I might never understand, better importing 
> the new version, get it to work and see if the bug is still there"

And it works ok with the new version, right?

> > With that said, now is a good opportunity to import the newer ACPI-CA,
> > because the 3.0 branch is cut, and there's a lot of time to stabilize
> > the new one for -current.  But it's another thing to nail down the
> > real problem.
> > 
> > I'd like to work on importing a newer ACPI-CA for -current in a week
> > or two.
> 
> I was also planning to write a driver for the processor object, by the way!

When you finish writing it, I'm glad to review it.

> O sewa ni narimashita ! :)
> Sayonara !
> Vincent

Thanks,
---
Takayoshi Kochi