From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932534AbcBIRGd (ORCPT ); Tue, 9 Feb 2016 12:06:33 -0500 Received: from mail-wm0-f46.google.com ([74.125.82.46]:37884 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932397AbcBIRGa (ORCPT ); Tue, 9 Feb 2016 12:06:30 -0500 Subject: Re: Nokia N900: Proper C-states To: Tony Lindgren References: <201601021526.28687@pali> <56884890.9080306@linaro.org> <20160209155619.GG19432@atomide.com> Cc: =?UTF-8?Q?Pali_Roh=c3=a1r?= , Jean Pihet , Santosh Shilimkar , Kevin Hilman , Nishanth Menon , Pavel Machel , Aaro Koskinen , Sebastian Reichel , Ivaylo Dimitrov , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, Lorenzo Pieralisi From: Daniel Lezcano Message-ID: <56BA1C92.4040202@linaro.org> Date: Tue, 9 Feb 2016 18:06:26 +0100 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160209155619.GG19432@atomide.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/09/2016 04:56 PM, Tony Lindgren wrote: > * Daniel Lezcano [160102 14:01]: >> On 01/02/2016 03:26 PM, Pali Rohár wrote: >>> Hello, >>> >>> due to this Daniel Lezcano commit (ARM: OMAP3: cpuidle - remove rx51 >>> cpuidle parameters table) >>> >>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=231900afba52d6faddfb480cde4132d4edc089bc >>> >>> we need patch cpuidle34xx.c code to fix commit for Nokia N900. See: >>> >>> https://github.com/pali/linux-n900/commit/e147fd4b678f1f3d7a5235287910960bd41e04dc >>> >>> As Nokia N900 code is converting from legacy board code to DST, I would >>> like to know how to patch correctly omap3_idle_driver in DTS with >>> correct values measured for Nokia N900. Thanks! > > I'm almost certain those values are not n900 specific but should be > used for omap3430 in general. > >> the conversion to the DT based arm cpuidle driver could be a bit complex >> with one issue (index 0 != cpu_do_idle()) and one performance regression >> (cpu_pm_enter/exit will be called in retention mode, even if this is not >> needed). >> >> It will result in a PM code only on one side and on the other side, the >> generic cpuidle-arm.c driver will be used instead with the DT definition. It >> is worth to the conversion because the result will be nice IMO. >> >> Added Lorenzo who is initially author of the arm generic driver. We already >> discussed in the past about those two issues above and I think this is >> something we should improve. > > While this conversion process is going on, we could just add > omap3430_idle_driver and set that based on cpu_is_omap3430() > in omap3_idle_init(). Yes, that could be a temporary alternative. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog