RE: [acpi-jp 3117] RE: ACPI-CA 20040311 imported

Here's an example of ASL recursion:

Method(PWUP,0,NotSerialized)
{
    If(LAnd(\_SB.PCI0.CBS0.PWRS,\_SB.PCI0.CBS1.PWRS))
    {
        If(LNot(And(_ADR /* \_SB.PCI0.CBS0._ADR */,0xFFFF)))
        {
            And(MCTL /* \_SB.PCI0.CBS0.MCTL */,0x7C,Local0)
            Or(Local0,BMCL /* \_SB.PCI0.CBS0.BMCL */,MCTL /*
\_SB.PCI0.CBS0.MCTL */)
        }
        Else
        {
            \_SB.PCI0.CBS0.PWUP()
        }
    }
}
-----Original Message-----
From: Moore, Robert 
Sent: Thursday, March 25, 2004 9:32 AM
To: 'Nate Lawson'
Cc: acpi-jp_at_jp.FreeBSD.org; current_at_freebsd.org
Subject: RE: [acpi-jp 3117] RE: ACPI-CA 20040311 imported

I think I've seen recursion in some IBM ASL.

Also, since iASL reports a remark when it detects a recursive call,
every now and then someone complains.

Bob


-----Original Message-----
From: Nate Lawson [mailto:nate_at_root.org] 
Sent: Thursday, March 18, 2004 11:11 PM
To: Moore, Robert
Cc: acpi-jp_at_jp.FreeBSD.org; current_at_freebsd.org
Subject: Re: [acpi-jp 3117] RE: ACPI-CA 20040311 imported

> -----Original Message-----
> From: owner-acpi-jp_at_jp.FreeBSD.org
[mailto:owner-acpi-jp_at_jp.FreeBSD.org]
> On Behalf Of Nate Lawson
> Sent: Thursday, March 18, 2004 10:47 AM
> To: current_at_freebsd.org; acpi-jp_at_jp.FreeBSD.org
> Subject: [acpi-jp 3116] ACPI-CA 20040311 imported
>
> See src/sys/contrib/dev/acpica/CHANGES.txt for specific changes.
>
> The main change is that we now support _OSI to announce we're
compatible
> with all the NT-derived MS systems.  Also, we now serialize all method
> execution as some ASL depends on this behavior.  The MS interpreter
> doesn't support parallel execution, hence this matches their behavior.
>
> If there are problems with these features, please try the tunables:
>
> hw.acpi.osi_method
> hw.acpi.serialize_methods
>
> You can disable each feature by setting it to 0 at the loader prompt
or
> loader.conf.

On Thu, 18 Mar 2004, Moore, Robert wrote:
> 1) If you serialize all methods by default, you will prohibit
recursive
> methods.  That's why we made this an option for Linux, and the default
> is to allow reentrant methods.
>
> 2) We are not really sure about the MS interpreter.  They claim that
> they support reentrant methods and allow multiple threads to execute.
> But we see problems with the coding of reentrant ASL methods that
imply
> that that multiple threads never execute control methods concurrently
on
> Win*

Interesting.  Do you know of any ASL that uses recursive methods?  I
haven't ever found any like that.  If you don't have a counter-example,
I'm happy to let this sit in the tree for a little while to see if it
solves problems or breaks things for people.  If we don't turn it on by
default, it won't get the testing it needs.

-Nate