From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61035C43603 for ; Tue, 10 Dec 2019 14:50:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3367920637 for ; Tue, 10 Dec 2019 14:50:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vYOET9ni" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727159AbfLJOuR (ORCPT ); Tue, 10 Dec 2019 09:50:17 -0500 Received: from mail-io1-f66.google.com ([209.85.166.66]:46245 "EHLO mail-io1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727145AbfLJOuR (ORCPT ); Tue, 10 Dec 2019 09:50:17 -0500 Received: by mail-io1-f66.google.com with SMTP id t26so7630172ioi.13; Tue, 10 Dec 2019 06:50:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EopU7gHpRZaFwvjzHn1zzfgni4g/N/UohJ2TWwA1/m0=; b=vYOET9ni2r/x+WsiXrE22CAhuCTJnazMZnB6tLnbsJJvL+/CzhU1nqV1u6g92L2TNW 9sAEay9IDtRMUHOayxwKfjT2r9lN4koXTLKoLVKDzZBZDWLgiNin4xODz2NgytLN1/72 hSSQLiWGAvpQ7f2Y//zUXwIJC82LiIBHDcfAmnjHonbk5FQwzEZiOjSEo0561jYZhJQq 9yWghFa/pG9x9CtBfd3VU/Oe4JciVfoezbgYDgf4VpZQxVfHPdKyvhhMhqOAQUU3XcXu VPxq27c1c96xJRk8NXIqa8i9pLr3WYopimSbG/2WEAdS8VXGN5q5zikx6CNmL00QOCP9 dCMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EopU7gHpRZaFwvjzHn1zzfgni4g/N/UohJ2TWwA1/m0=; b=pZ5JkB9yXAmlgCcVOaYlWXNeqyJDdFlc9JGT8462BRLf5t+5gAUM7FoNsaOckUTU2i HSfkW/SM9WBY9L3Ewvxc6Peiv8YP7dfL6FaATIFF7JFezO/zf73pW1er5Q3iL3emiWAI OsdFspy6BFmNrqeSCWfJw7E5DKFj9gG4w6GGemR3IZf0OYE9guqo9RGPZ1+/XM9wwcZi A5MQTKf5+DdeEcVi4YvzQU/EvX+kx9dDnRituhAmfELakFMyBbwA9VuGN8PtZ7TMzT5A mKOfVioxTgPtoIbE4AbWTrPRoFIEXVogQzRwoLO7WoZEbH6Igd+v/NjPq9uUKBn2EQIh 6e5w== X-Gm-Message-State: APjAAAX3fKvm/QgQ6nsN2Bp8TjqKemxUXnHPp+GZzGxX6MY569tLyUVF v3YNfw0CT40zEcPJy9oswAepx4St1dM9sn/vlZA= X-Google-Smtp-Source: APXvYqyg+Q4PiSVD+TRIfNYYQb9a80Ve7CWTpf0XRMvR2kxSQvCVSYQFM+LAKN06jjFUHKWALrHPxHKTq7zl/ShAp7s= X-Received: by 2002:a6b:e008:: with SMTP id z8mr24398133iog.246.1575989416712; Tue, 10 Dec 2019 06:50:16 -0800 (PST) MIME-Version: 1.0 References: <20191101143126.2549-1-linux.amoon@gmail.com> <7hfthtrvvv.fsf@baylibre.com> In-Reply-To: From: Anand Moon Date: Tue, 10 Dec 2019 20:20:05 +0530 Message-ID: Subject: Re: [RFC-next 0/1] Odroid C2: Enable DVFS for cpu To: Neil Armstrong Cc: Kevin Hilman , Rob Herring , Martin Blumenstingl , Jerome Brunet , devicetree , linux-arm-kernel , linux-amlogic@lists.infradead.org, Linux Kernel Content-Type: text/plain; charset="UTF-8" Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Neil / Kevin, On Tue, 10 Dec 2019 at 14:13, Neil Armstrong wrote: > > On 09/12/2019 23:12, Kevin Hilman wrote: > > Anand Moon writes: > > > >> Some how this patch got lost, so resend this again. > >> > >> [0] https://patchwork.kernel.org/patch/11136545/ > >> > >> This patch enable DVFS on GXBB Odroid C2. > >> > >> DVFS has been tested by running the arm64 cpuburn > >> [1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S > >> PM-QA testing > >> [2] https://git.linaro.org/power/pm-qa.git [cpufreq testcase] > >> > >> Tested on latest U-Boot 2019.07-1 (Aug 01 2019 - 23:58:01 +0000) Arch Linux ARM > > > > Have you tested with the Harkernel u-boot? > > > > Last I remember, enabling CPUfreq will cause system hangs with the > > Hardkernel u-boot because of improperly enabled frequencies, so I'm not > > terribly inclined to merge this patch. HK u-boot have many issue with loading the kernel, with load address *it's really hard to build the kernel for HK u-boot*, to get the configuration correctly. Well I have tested with mainline u-boot with latest ATF . I would prefer mainline u-boot for all the Amlogic SBC, since they sync with latest driver changes. > > Same, since the bootloader boots with the max supported freq of the board, > there is not real need of DVFS except for specific low-power use-cases. > > And still, some early boards still use the bad SCPI freq table, we can't break them. > > Neil > I will leave this to your expert domain knowledge if you want to enable this now. Here is output of on the latest kernel. *cpupower* # cpupower frequency-info analyzing CPU 0: driver: scpi-cpufreq CPUs which run at the same hardware frequency: 0 1 2 3 CPUs which need to have their frequency coordinated by software: 0 1 2 3 maximum transition latency: 200 us hardware limits: 100.0 MHz - 1.54 GHz available frequency steps: 100.0 MHz, 250 MHz, 500 MHz, 1000 MHz, 1.30 GHz, 1.54 GHz available cpufreq governors: conservative ondemand userspace powersave performance schedutil current policy: frequency should be within 100.0 MHz and 100.0 MHz. The governor "ondemand" may decide which speed to use within this range. current CPU frequency: 100.0 MHz (asserted by call to hardware) *powertop* # powertop Package | CPU 0 100 MHz 47.1% | 100 MHz 41.5% 250 MHz 0.0% | 250 MHz 0.0% 500 MHz 0.0% | 500 MHz 0.0% 1000 MHz 0.0% | 1000 MHz 0.0% 1296 MHz 0.0% | 1296 MHz 0.0% 1.54 GHz 0.0% | 1.54 GHz 0.0% Idle 52.9% | Idle 58.5% > > > >> Patch based on my next-20191031 for 5.5.x kernel. > >> Hope this is not late entry. > > > > Re: "too late". FYI... when you post things as RFC, it means you're > > looking for comments (Request For Comment) but that it's not intended > > for merging. Ok thanks for this input. > > > > I didn't see any comments on this, but I also didn't see a non-RFC > > follow-up, so I didn't queue it for v5.5. No problem. > > > > Kevin > > > -Anand