Re: [PATCH]acpi c-states: Fix ACPI C3 is wrongly mapped to C2

Youquan,Song
2009-12-14T02:26:31Z

> > That's true, if CPU has more 3 states such as C3, C6, C7, there are
> > all mapped to ACPI C3. But the current situation is that if platform
> > does NOT support ACPI C2, the user interface /sys show us ACPI C2 is
> > supported which actual is ACPI C3.
> >
> > As you know, ACPI C3 and ACPI C2 have much different, such as: BUS SNOOP
> > or not, ACPI C3 has better power saving etc. we should not mix them.
>
> Yes, but what happens if there are two states of type C2? The whole concept
> of "type C<number>" and "state C<number>" was broken from the beginning...

Sorry. In my mind, there is no two states of ACPI C2. If processor C3
above are mapped to ACPI C3, so processor C1 is mapped to ACPI C1,
processor C2 is mapped to ACPI C2.
Len Brown, Am I right?

If I am wrong, I will file another patches for it.

-Youquan