improve cx_lowest logic

[Andriy Gapon]

on 05/09/2012 20:41 Kevin Oberman said the following:
> On Wed, Sep 5, 2012 at 9:32 AM, Andriy Gapon <avg at freebsd.org> wrote:
>> on 05/09/2012 19:23 Kevin Oberman said the following:
>>> On Wed, Sep 5, 2012 at 9:12 AM, Andriy Gapon <avg at freebsd.org> wrote:
>>>> on 05/09/2012 18:17 Kevin Oberman said the following:
>>>>> Thanks so much! This should finally make Cx states work on my
>>>>> ThinkPad! I really appreciate it. Guess it's time to do my weekly
>>>>> upgrade of this system.
>>>>
>>>> I haven't sneaked in that other commit :-(
>>>
>>> Oops! :-(
>>>
>>> Oh, well. At least it should make it to /base/stable/9 soon. Right???
>>> (I only run release/ or releng/ or for an occasional test.)
>>>
>>
>> It's already in stable/9 :)
> 
> Ahh! I now see C3/109, but I see some strange behavior. When on AC
> power, only C1/1 and C2/104 are available, but cx_lowest is C3, even
> though C3 is not available. If I switch to battery, C1/1, C2/80 and
> C3/109 are available (???), but cx_lowest is set to C2. I find the Cx
> value sets a bit odd, but the setting of cx_lowest appears to be a
> bug, at least to me. I can manually set cx_lowest to C3 and I actually
> use C3.
> 
> My suspicion is that there is either a race or a logic issue where
> x_lowest is reset to the lowest value before the available Cx values
> are set, so cx_lowest is always set the the lowest Cx state from the
> previous power configuration. (This is a guess, but it fits what I am
> seeing very well.)
> 

Hmm, this looks like the older behavior.
What revision are you at?  Also, any local ACPI-related patches?

-- 
Andriy Gapon