From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Turquette Subject: Re: [PATCH 6/6 v6] cpufreq, highbank: add support for highbank cpufreq Date: Wed, 28 Nov 2012 20:34:36 -0800 Message-ID: <20121129043436.21126.714@nucleus> References: <1351631056-25938-1-git-send-email-mark.langsdorf@calxeda.com> <1354046672-7392-1-git-send-email-mark.langsdorf@calxeda.com> <1354046672-7392-7-git-send-email-mark.langsdorf@calxeda.com> <20121128023240.GA28170@S2100-06.ap.freescale.net> <50B60E9C.9000405@calxeda.com> <20121128145759.GB28170@S2100-06.ap.freescale.net> <20121128151741.GC28170@S2100-06.ap.freescale.net> <20121128160115.21126.3841@nucleus> <20121129015133.GD28170@S2100-06.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121129015133.GD28170-+NayF8gZjK2ctlrPMvKcciBecyulp+rMXqFh9Ls21Oc@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Shawn Guo Cc: Mark Langsdorf , "linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "cpufreq-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org Quoting Shawn Guo (2012-11-28 17:51:36) > > The notifiers in the clk framework might be a better place for this than > > just simply hacking the logic into the .set_rate callback. > > Ah, right. How did I forget about that nice piece? > > > I haven't looked at the definition of hb_voltage_change but does the > > call graph make any clk api calls? Are you talking over i2c to a > > regulator? If so then you'll probably hit the same reentrancy problem I > > hit when trying to make a general solution. > > So, how is your "reentrancy in the common clk framework" series[1] > going on? Haven't seen any update since August. > I've begun to look at a dvfs api that builds on top of the clock framework, as opposed to using clk_set_rate as the dvfs api itself. This eliminates the need for reentrancy, at least for the dvfs case. I'll post more when I have it. Honestly the reentrancy stuff was just too ugly. I might try again some day but for now I'm thinking a less radical approach deserves consideration. Thanks, Mike > Shawn > > [1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/182198