Comment 2 for bug 833644

Hi Colin,

The _CST are not located in DSDT but in a SSDT. Maybe I can get a
machine and send you a screenshot if I can get a Sandy Bridge - probably
need to install a Windows because some utilities only run on Windows :(

Any idea whom I can borrow a Sandy bridge system from?

On Thu, 2011-08-25 at 13:34 +0000, Colin King wrote:
> @Alex,
>
> So I've scanned a bunch of machines and some have P_LVL2_LAT and
> P_LVL3_LAT defined as non supporting C2/C3 and the DSDT does not contain
> a _CST. Some newer CPUs such a Sandybridge are configured like this
> and the Intel idle driver figures out the number of C states from the
> CPU id rather than trusting the firmware provided data (be it existent
> or not).
>
> So.. perhaps I could phrase the warning something like:
>
> "FADT P_LVL2_LAT is 101, a value > 100 indicates that the C2 state is
> not defined in the FADT. C states either defined in the _CST object or
> determined by the kernel from the CPU id."
>
> ** Changed in: fwts (Ubuntu)
> Status: In Progress => Incomplete
>