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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 1A9A8C4CEC9 for ; Tue, 17 Sep 2019 13:05:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3A4D2171F for ; Tue, 17 Sep 2019 13:05:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727042AbfIQNFp (ORCPT ); Tue, 17 Sep 2019 09:05:45 -0400 Received: from 1.mo179.mail-out.ovh.net ([178.33.111.220]:58134 "EHLO 1.mo179.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727469AbfIQNFp (ORCPT ); Tue, 17 Sep 2019 09:05:45 -0400 Received: from player699.ha.ovh.net (unknown [10.108.35.210]) by mo179.mail-out.ovh.net (Postfix) with ESMTP id D39C014214C for ; Tue, 17 Sep 2019 15:05:42 +0200 (CEST) Received: from qperret.net (115.ip-51-255-42.eu [51.255.42.115]) (Authenticated sender: qperret@qperret.net) by player699.ha.ovh.net (Postfix) with ESMTPSA id 73C3D9E63A6C; Tue, 17 Sep 2019 13:05:27 +0000 (UTC) Date: Tue, 17 Sep 2019 15:05:22 +0200 From: Quentin Perret To: Daniel Lezcano Cc: Sudeep Holla , Amit Kucheria , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, bjorn.andersson@linaro.org, edubezval@gmail.com, agross@kernel.org, tdas@codeaurora.org, swboyd@chromium.org, ilina@codeaurora.org, "Rafael J. Wysocki" , Viresh Kumar , Zhang Rui , linux-pm@vger.kernel.org Subject: Re: [PATCH 5/5] cpufreq: qcom-hw: Move driver initialisation earlier Message-ID: <20190917130522.GA31601@qperret.net> References: <20190917093412.GA24757@bogus> <58e60ca4-9615-bbdf-5fe7-2a0e1d7f48d8@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58e60ca4-9615-bbdf-5fe7-2a0e1d7f48d8@linaro.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-Ovh-Tracer-Id: 15719251551264529282 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedufedrudeigdefgecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi Daniel On Tuesday 17 Sep 2019 at 14:47:22 (+0200), Daniel Lezcano wrote: > > Hi Sudeep, > > On 17/09/2019 11:34, Sudeep Holla wrote: > > On Thu, Sep 12, 2019 at 04:02:34AM +0530, Amit Kucheria wrote: > >> Allow qcom-hw driver to initialise right after the cpufreq and thermal > >> subsystems are initialised in core_initcall so we get earlier access to > >> thermal mitigation. > >> > >> Signed-off-by: Amit Kucheria > >> --- > >> drivers/cpufreq/qcom-cpufreq-hw.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c > >> index 4b0b50403901..04676cc82ba6 100644 > >> --- a/drivers/cpufreq/qcom-cpufreq-hw.c > >> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c > >> @@ -327,7 +327,7 @@ static int __init qcom_cpufreq_hw_init(void) > >> { > >> return platform_driver_register(&qcom_cpufreq_hw_driver); > >> } > >> -device_initcall(qcom_cpufreq_hw_init); > >> +postcore_initcall(qcom_cpufreq_hw_init); > > > > I am fine with core framework initcall pushed to earlier initcall levels > > if required, but for individual/platform specific drivers I am not so > > happy to see that. > > > > This goes against the grand plan of single common kernel strategy by > > Android moving all drivers as modules. We might decide to make this > > a module. > > module = mounted file system = very late initialization > > Is that the plan? Force every driver to load too late? > > There are core drivers which must be loaded as soon as possible. If the > qcom driver is one of them, then what is the problem? > > "The grand plan" will have to solve this first before doing the module > move. > > > Also there are few cpufreq drivers that are modules. Will > > they have issues ? If not, why do we need this change at all. > > Because some boards don't have thermal issues with the cpufreq drivers > as module, other boards have. > > > Needing > > thermal mitigation during boot this earlier is still too much of > > expectation, I would rather boot slowly than relying on this feature. > > And what if we want to boot faster? The boot time is one of a key point > of benchmark. Could you share test results for this ? It'd be nice to see what if the gains in boot time outweight the additional pain for android folks ... Thanks, Quentin