From mboxrd@z Thu Jan 1 00:00:00 1970 From: marek.vasut@gmail.com (Marek Vasut) Date: Sat, 4 Sep 2010 04:31:49 +0200 Subject: [Openpxa-users] Colibri PXA320 Power management question In-Reply-To: <4C7FC606.20904@compulab.co.il> References: <20100902152705.GC5809@rakim.wolfsonmicro.main> <4C7FC606.20904@compulab.co.il> Message-ID: <201009040431.49798.marek.vasut@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Dne ?t 2. z??? 2010 17:43:02 Mike Rapoport napsal(a): > 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. Considering the CPU and the regulator are compatible and you wont fry the CPU. In that case, you use cpufreq indeed.