Message-ID: <1362193098.2407.27.camel@bilhuang-vm1>
Subject: Re: [PATCH 2/5] clk: notifier handler for dynamic voltage scaling
From: Bill Huang <bilhuang@nvidia.com>
To: Stephen Warren <swarren@wwwdotorg.org>
CC: Mike Turquette <mturquette@linaro.org>,
        "linaro-dev@lists.linaro.org" <linaro-dev@lists.linaro.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
        "patches@linaro.org" <patches@linaro.org>
Date: Fri, 1 Mar 2013 18:58:18 -0800
In-Reply-To: <5131143D.2060904@wwwdotorg.org>
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On Sat, 2013-03-02 at 04:49 +0800, Stephen Warren wrote:
> On 03/01/2013 02:41 AM, Bill Huang wrote:
> > On Thu, 2013-02-28 at 12:49 +0800, Mike Turquette wrote:
> >> There are three prerequisites to using this feature:
> >>
> >> 1) the affected clocks must be using the common clk framework
> >> 2) voltage must be scaled using the regulator framework
> >> 3) clock frequency and regulator voltage values must be paired via the
> >> OPP library
> > 
> > Just a note, Tegra Core won't meet prerequisite #3 since each regulator
> > voltage values is associated with clocks driving those many sub-HW
> > blocks in it.
> 
> Perhaps that "just" means extending the dvfs.c code here to iterate over
> each clock consumer (rather than each clock provider), and having each
> set a minimum voltage (rather than a specific voltage), and having the
> regulator core apply the maximum of those minimum constraints?
> 
> Or something like that anyway.

Thanks, I'll think about this or maybe study a bit, it sounds like we
can leverage existing api in regulator framework (which I don't know) to
do what you've proposed, please clarify if I misunderstand.
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