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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B280BC33CA5 for ; Fri, 10 Jan 2020 11:54:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 886AA20848 for ; Fri, 10 Jan 2020 11:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728223AbgAJLyw (ORCPT ); Fri, 10 Jan 2020 06:54:52 -0500 Received: from foss.arm.com ([217.140.110.172]:43242 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728183AbgAJLyu (ORCPT ); Fri, 10 Jan 2020 06:54:50 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2F6861063; Fri, 10 Jan 2020 03:54:50 -0800 (PST) Received: from [192.168.1.123] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C60173F534; Fri, 10 Jan 2020 03:54:48 -0800 (PST) Subject: Re: [PATCH v1] arch_topology: Adjust initial CPU capacities with current freq To: Sudeep Holla , Jeffy Chen Cc: linux-kernel@vger.kernel.org, Brian Norris , Marc Zyngier , Douglas Anderson , Heiko Stuebner , Greg Kroah-Hartman , "Rafael J. Wysocki" References: <20200109075214.31943-1-jeffy.chen@rock-chips.com> <20200110113711.GB39451@bogus> From: Robin Murphy Message-ID: <9edb57be-97bc-f0bd-3edd-854dfc8c780f@arm.com> Date: Fri, 10 Jan 2020 11:54:48 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <20200110113711.GB39451@bogus> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-01-10 11:37 am, Sudeep Holla wrote: > On Thu, Jan 09, 2020 at 03:52:14PM +0800, Jeffy Chen wrote: >> The CPU freqs are not supposed to change before cpufreq policies >> properly registered, meaning that they should be used to calculate the >> initial CPU capacities. >> >> Doing this helps choosing the best CPU during early boot, especially >> for the initramfs decompressing. >> >> Signed-off-by: Jeffy Chen > > [...] > >> @@ -146,10 +153,15 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) >> return false; >> } >> } >> - capacity_scale = max(cpu_capacity, capacity_scale); >> raw_capacity[cpu] = cpu_capacity; >> pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n", >> cpu_node, raw_capacity[cpu]); >> + >> + cpu_clk = of_clk_get(cpu_node, 0); >> + if (!PTR_ERR_OR_ZERO(cpu_clk)) >> + per_cpu(max_freq, cpu) = clk_get_rate(cpu_clk) / 1000; >> + >> + clk_put(cpu_clk); > > I don't like to assume DVFS to be supplied only using 'clk'. So NACK! > We have other non-clk mechanism for CPU DVFS and this needs to simply > use cpufreq APIs to get frequency value if required. ...but in this case, as soon as cpufreq is ready the problem is gone anyway, because it sees the big cluster's clock rate is way out-of-spec and bumps it up to a sane OPP. It really is unfortunate that so many RK3399 images out there are using the broken firmware combination that manages to miss out the boot-time PLL setup altogether. Robin.