Re: ACPI_STRICT_COMPLIANCE (was RE: RE: ACPI -- Workaround forbroken DSDT)

[Bruno Ducrot <ducrot-kk6yZipjEM5g9hUCZPvPmw@public.gmane.org>]

On Thu, Feb 12, 2004 at 06:08:41PM -0600, Cagle, John (ISS-Houston) wrote:
> From: Bruno Ducrot
> > On Wed, Feb 11, 2004 at 11:33:16PM -0600, Cagle, John 
> > (ISS-Houston) wrote:
> > > From: Yu, Luming [mailto:luming.yu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org] 
> > > > 
> > > > > that would be a kernel command line option to do the same thing.
> > > > > ACPI_STRICT=ON?
> > > > 
> > > > It is unfeasible.
> > > 
> > > Care to elaborate?
> > > 
> > 
> > How you will handle the toshiba return bug?
> 
> I'm not familiar with that specific bug, and I want to make it clear I
> was not suggesting that we remove any existing workarounds.

Sorry, I should explain more, then.

> 
> I was suggesting that having a kernel command line option (to control
> the strict-ness of the ACPI implementation) will make it a lot easier
> for OEM's to test their AML under Linux.  Assuming, of course, that the
> default behavior of the ACPI driver is "relaxed", which it is not
> currently.
> 

The 'toshiba return bug' is something like that:

Method(FOO) {
	return (0)
}

Method(BAR) {
	FOO()
}

If ACPI is pedantic, BAR return nothing.

On some implementation of the AML interpreter found on no-named OS, BAR
will return 0.  Also, if now you have

Method(BAZ) {
	DoSomething
	FOO()
	DoSomethingElse
	Return(1)
}

Then if ACPI is pedantic, the DoSomethingElse will be executed, and 1
will be returned, whereas on some no-named AML interpreter the DoSomethingElse
path will not be executed, and 0 will be returned.  Also, it's hard to
know what is exactly the intention of the BIOS writer on such ASL
statements.

It can be possible that the no-named AML interpreter fixed that
issue (I believe this is the case), whereas it do not fix others.

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.


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