Re: Suspend code ordering (again)

From: Robert Hancock
Date: Thu Dec 27 2007 - 19:26:35 EST


Rafael J. Wysocki wrote:
Also, as was pointed out, pre-Vista versions of Windows follow ACPI 1.0 and Vista follows 3.0, so 2.0 doesn't really matter since BIOS people won't test against it. 1.0 specifies that _PTS is to be called before suspending devices and 3.0 says that the AML must not depend on any specific device power state, so in both cases it should be safe to call _PTS before suspending, no?

Well, IMO, if we take one option only (whichever that is) and there are systems
that follow the other one, they will likely break.

Apart from this, there are BIOSes that openly claim ACPI 2.0 support (for
example, the one in my HP nx6325 does that) and they may actually prefer the
post-ACPI-1.0 ordering even if they work with the pre-ACPI-2.0 one.

I doubt they would prefer the later ordering in any way that matters, if the Windows version they were designed for uses the earlier ordering.

It would be best if somebody could manage to find out what ordering Windows XP (and Windows Vista, for good measure) actually use, then we could just use that. Virtual machine trickery might be an option - the only complication being that it'll be using the DSDT for the fake machine and not the real one..

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Robert Hancock Saskatoon, SK, Canada
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