From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 1/9] spi/pxa2xx: don't use subys initcall for driver init Date: Wed, 24 Nov 2010 08:30:37 -0700 Message-ID: References: <1290597207-29838-1-git-send-email-bigeasy@linutronix.de> <1290597207-29838-2-git-send-email-bigeasy@linutronix.de> <4CED1C95.8070300@linutronix.de> <20101124141623.GH24970@rakim.wolfsonmicro.main> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: David Brownell , eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Sebastian Andrzej Siewior , Haojian Zhuang , linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, sodaville-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Dirk Brandewie , spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, drwyrm-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org To: Mark Brown Return-path: In-Reply-To: <20101124141623.GH24970-HF5t3jzXg/6ND3a5+9QAFujbO/Zr0HzV@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Wed, Nov 24, 2010 at 7:16 AM, Mark Brown wrote: > On Wed, Nov 24, 2010 at 03:09:25PM +0100, Sebastian Andrzej Siewior wrote: > >> I've been pointed out to this commit but I don't understand _why_. >> The part I don't get is "so it can be used with cpufreq". Is it >> refered to a driver or the subsystem as it? > > We need the regulators for the CPU rails to start before the cpufreq > driver starts so cpufreq can talk to them, and since the regulators may > be SPI attached this means we also need the SPI controller to start > before cpufreq. =A0cpufreq starts at vanilla init time. > > There's an approach being looked at for handling this for devices but > for deviceless stuff like cpufreq we've nothing. It would be easy enough to defer cpufreq initialization based on some platform defined criteria. It's just an initcall. However, I don't know what the impact area is for subsystems that depend on cpufreq. Are there drivers that depend on cpufreq before initialized? g. -- = Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. ---------------------------------------------------------------------------= --- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev