From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752311AbcABWAy (ORCPT ); Sat, 2 Jan 2016 17:00:54 -0500 Received: from mail-wm0-f46.google.com ([74.125.82.46]:34033 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbcABWAw (ORCPT ); Sat, 2 Jan 2016 17:00:52 -0500 Subject: Re: Nokia N900: Proper C-states To: =?UTF-8?Q?Pali_Roh=c3=a1r?= , Tony Lindgren References: <201601021526.28687@pali> Cc: 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: <56884890.9080306@linaro.org> Date: Sat, 2 Jan 2016 23:00:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <201601021526.28687@pali> 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 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! Hi Pali, 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. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog