Re: PowerOP, Intro 0/3

[Matthew Locke <matt@nomadgs.com>]

On Aug 26, 2006, at 1:38 PM, Pavel Machek wrote:

> Hi!
>
>>>> PowerOP Core upper layer interface provides the
>>>> following capabilities:
>>>> - to register an operating point by passing an
>>>> idenificator of the point
>>>> represened by a string and arbitrary substet of power
>>>> paremeters available on a
>>>> certain platform by a string (parameter name) and
>>>> value pairs.
>>>> - to unregister operating point by name
>>>> - to set operating point by name
>>>> - to get values of arbitrary subset of platform power
>>>> parameters associated
>>>> this  a point (point is passed by name or NULL to get
>>>> current parameter values
>>>> from hw)
>>>
>>> I do not think this can work in notebook world, sorry.
>>> You'll just get
>>> way too many operating points.
>> The only feature for notebook world currently presented
>> in the kernel is CPUFreq. CPUFreq PowerOP integration
>
> Actually no. In the notebook world, we do cpufreq, selective powerdown
> of devices (/sys/**/power/state), and suspend-to-ram/disk (not sure if
> it applies to you, but at least some powerop versions wanted to
> replace that).


The main point is that you won't get too many operating points.  You 
will get the number of operating points the x86 port of PowerOP chooses 
to have.  In the cpufreq/PowerOP integration patches you get the same 
number of operating points you have today in cpufreq.   We query ACPI 
for the list or use the hardcoded table.  Also, if we provide a 
userspace API for creating operating points,  distro's can create 
additional operating points that make sense for some specific use cases 
they would like to optimize around.


Matt