Re: [PATCH] PM / OPP: improve introductory documentation

From: Randy Dunlap
Date: Tue Feb 26 2013 - 18:38:53 EST

On 02/26/13 15:10, Nishanth Menon wrote:
> On 14:43-20130226, Randy Dunlap wrote:
>> On 02/26/13 09:37, Nishanth Menon wrote:
> [..]
>>> 1. Introduction
>>> ===============
>>> +1.1 What is an Operating Performance Point (OPP)?
>>> +
>>> Complex SoCs of today consists of a multiple sub-modules working in conjunction.
>>> In an operational system executing varied use cases, not all modules in the SoC
>>> need to function at their highest performing frequency all the time. To
>>> facilitate this, sub-modules in a SoC are grouped into domains, allowing some
>>> domains to run at lower voltage and frequency while other domains are loaded
>>> -more. The set of discrete tuples consisting of frequency and voltage pairs that
>>> +more.
>> huh???
> I split the definition line to it's own paragraph below. But, I think
> you intend to say we could improve better the remaining paragraph.
> Could you elaborate your thoughts?

"while other domains are loaded more." Some people probably understand
that OK; I dunno. I would rather see it written out more verbosely, e.g.:

"while other domains run at voltage/frequency pairs that are higher."

but partly I was confused by the diff(1) lines. my bad :(

>>> +
>>> +The set of discrete tuples consisting of frequency and voltage pairs that
>>> the device will support per domain are called Operating Performance Points or
>>> OPPs.
>>> +As an example:
>>> +Let us consider an MPU device which supports the following:
>>> +{300MHz at minimum voltage of 1V}, {800MHz at minimum voltage of 1.2V},
>>> +{1GHz at minimum voltage of 1.3V}
>>> +
>>> +We can represent these as three OPPs as the following {Hz, uV} tuples:
>>> +{300000000, 1000000}
>>> +{600000000, 1200000}
>> 800000000
>>> +{100000000, 1300000}
>> 1000000000 ??
> Thanks for catching it. will fix it in next rev.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at