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From: w.sang@pengutronix.de (Wolfram Sang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] Add cpuidle support for at91
Date: Fri, 2 Oct 2009 10:46:03 +0200	[thread overview]
Message-ID: <20091002084603.GA3179@pengutronix.de> (raw)
In-Reply-To: <4AC35582.8000404@atmel.com>


> In other words, only state "wait-for-interrupt *and* RAM self refresh"
> brings some more power saving. Indeed, cpu_do_idle() that correspond to
> the "WFI" state was already the way of dealing with idle cpu, even
> without your patch. Am I correct ?

Yes, but it has a higher exit latency. Those data is provided to the cpuidle
framework, so it can decide which state to use.

I wonder if other people can confirm a similar amount of power savings? I am
trying to implement the RAM self refresh for i.MX and don't see much
improvment. I guess I still do something wrong...

Regards,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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  reply	other threads:[~2009-10-02  8:46 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1247680190-19674-1-git-send-email-albin.tonnerre@free-electrons.com>
     [not found] ` <200908111200.58866.marc.pignat@hevs.ch>
     [not found]   ` <20090812165700.GC4051@pc-ras4041.res.insa>
     [not found]     ` <200908130858.47487.marc.pignat@hevs.ch>
     [not found]       ` <20090813193241.GA5985@pc-ras4041.res.insa>
     [not found]         ` <20090909151417.GA4014@pc-ras4041.res.insa>
2009-09-29 14:15           ` [PATCH v2] Add cpuidle support for at91 Nicolas Ferre
2009-09-30 12:34             ` Albin Tonnerre
2009-09-30 12:56               ` Nicolas Ferre
2009-10-02  8:46                 ` Wolfram Sang [this message]
2009-10-09 10:53                 ` Albin Tonnerre
2009-10-22 15:47             ` Albin Tonnerre

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