On Fri, 2009-05-08 at 03:05 +0800, Witold Szczeponik wrote:
> yakui_zhao schrieb:
>
> > What you said is right. After applying that commit, the C169 device will
> > be switched to D3. And when the C169 device is switched to D3, the power
> > resource(C16D) will be turned off.
> > But unfortunately the _OFF object of C16D is bogus. In such case the
> > _STA method can't reflect the correct status of power resource and OS
> > will complain that the C169 device can't be switched to D3 state.
> > > Method (_OFF, 0, NotSerialized)
> > > {
> > Store (0x00, Local0)
> > > }
>
> I think this is the key to understanding what is going on here: it seems
> as if the BIOS does not allow for disabling the power resource through
> ACPI. I suspect the Linux' ACPI core tries to set the power resource to
> D3, then evaluates _STA, and relizes that something went wrong. But I
> am guessing here... Even more speculation: Windows either does not care
> or makes the transition from D0 to D3 only once..
Your guess is right.
If there is no boot option of "acpi.power_nocheck=1", the _STA method
will be evaluated to check whether the power resource is switched to the
correct state after the _ON/_OFF object is evaluated.
if the boot option of "acpi.power_nocheck=1" is added, the status check
will be skipped after the _ON/_OFF object is evaluated.
Thanks.
> .
>
> --- Witold
>
> >
> >
> > If we add the boot option of "acpi.power_nocheck=1", the status check
> > will be skipped in course of D0/D3 state transition.
> >
>
>
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