Re: ASUS M6800N: processor has only C1

Nate Lawson
2004-03-11T04:17:24Z

On Thu, 4 Mar 2004, Thomas Renninger wrote:
> Thomas Renninger wrote:
> > Your machine supports the C4 state.
> > Change the P_BLK in your DSDT to 0x06
> >
> > e.g.:
> > Processor (\_PR.CPU0, 0x01, 0x00001010, 0x07)
> > to:
> > Processor (\_PR.CPU0, 0x01, 0x00001010, 0x06)
> >
> > or use the patch from Pavel, posted on the 28.02.2004, 17:10.
> >
> > Unfortunately this won't enable the C4 state if you have one.
> > What do mainters say about supporting Cn processor states in the future?
>
> I am pretty sure this message will come up more often in future.
> Could it be that new mobile Intel processors support the C4 state ->
> therefore P_BLK = 0x07?
>
> Pavel's patch is a workaround, setting P_BLK back to 6, but isn't it
> worth a critical bug for supporting Cn states,
> as only supporting C0-C3 states offends the specification?

For FreeBSD, I took the approach that throttling requires P_BLK_LEN >= 4,
C2 requires >= 5, and C3 requires >= 6. Systems with higher values will
get C1-C3 but we will not support C4 on such systems. There are already
plenty of valid systems with _CST out in the real world (i.e. IBM Centrino
laptops) and so for someone to break the standard now is unacceptable.
Users will get C1-C3 on broken systems, which is good enough.

-Nate