From mboxrd@z Thu Jan 1 00:00:00 1970 From: mike@compulab.co.il (Mike Rapoport) Date: Thu, 02 Sep 2010 18:43:02 +0300 Subject: Colibri PXA320 Power management question In-Reply-To: <20100902152705.GC5809@rakim.wolfsonmicro.main> References: <20100902142203.GA8381@sirena.org.uk> <4C7FB7B5.2010301@compulab.co.il> <20100902152705.GC5809@rakim.wolfsonmicro.main> Message-ID: <4C7FC606.20904@compulab.co.il> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Mark Brown wrote: > On Thu, Sep 02, 2010 at 05:41:57PM +0300, Mike Rapoport wrote: >> Mark Brown wrote: > >>> The expectation in Linux is that voltage scaling will be done in >>> software using cpufreq rather than autonomously by the CPU. > >> PXA3xx has ability to automatically control certain regulators >> (almost) without software intervention. Setting the bits Yuri is >> talking about should enable CPU initiated i2c transactions upon >> frequency scaling events. > > Yes, exactly - what I'm saying is that Linux is set up to use cpufreq > rather than rely on the built in stuff. There's no contradiction here. The PXA3XX cpufreq implementation could trigger automatic voltage scaling. -- Sincerely yours, Mike.