Re: ACPI OSI disaster on latest HP laptops - critical temperature shutdown

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Fri, Aug 01, 2008 at 07:36:57PM -0300, Henrique de Moraes Holschuh wrote:
> On Fri, 01 Aug 2008, Len Brown wrote:
> > It is better to expose ourselves to the known tested Windows functionality
> > -- even if it seems arbitrary, at least it is tested.  The !Windows case
> > results in running _completely_ untested BIOS code.
> 
> Actually, we should masquerade properly as the latest Windows version
> available for that machine, then.  AFAIK, Windows does not set ALL the OSI
> strings, just one.  We ARE running untested code in some BIOSes because of
> it.

The BIOSes I've tested check _OSI in order of Windows release, which is 
consistent with Windows returning OSI strings for all previous versions. 
Do you have any examples that suggest this isn't the case?

> Maybe it would be better if every ACPICA-using OS defined a
> _OSI(NotWindows), plus the relevant Windows OSI string they want to support,
> and Intel would send word that this string is to be used ONLY to disable all
> Windows bug workarounds, not to activate or deactivate any specific
> functionality?

Not all BIOSes would support this, so we'd need to support the Windows 
workarounds anyway. At that point, there's no real benefit in having 
multiple codepaths.

-- 
Matthew Garrett | mjg59@srcf.ucam.org