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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 B90BDC47404 for ; Mon, 7 Oct 2019 22:58:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84A0D20867 for ; Mon, 7 Oct 2019 22:58:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="A94WXkxS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729584AbfJGW6C (ORCPT ); Mon, 7 Oct 2019 18:58:02 -0400 Received: from mail-pl1-f195.google.com ([209.85.214.195]:39971 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728980AbfJGW6C (ORCPT ); Mon, 7 Oct 2019 18:58:02 -0400 Received: by mail-pl1-f195.google.com with SMTP id d22so7572527pll.7 for ; Mon, 07 Oct 2019 15:58:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=HcljqBtqZ0n7Ky2kGCyvmwQmBy2Uww4x9f71GEl4Z8U=; b=A94WXkxSy/iySlIL7pQDbk5PyEHAV56d2+iR4LFGlii5+pbrJhkGI9GamLLoNTp12V g3e9CFHLq2AC728cDVClIDG2UxNJ5N3fH1AfNYALNjvbTpOSGmomeBb3eXQ08eJYoZk6 LU41rYaKI7Zmb1wKEoQWeSRAZ3gyy7X2TzCqPh41wNYsvmoupQFVQLsv8o0uOBqnW001 TNxb1jdGtt62cUx/R+dWLujDN5vi+hdJ/P/yrqpBibd5wr3zkNV+jGHXKk8g1j0fjxcL ShHB6G/+3rJf1OdL2Syq7gxBYqmuuArpeguVvRhkfckQBq3io5FGAOPIrLkybmRobMO9 hkIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=HcljqBtqZ0n7Ky2kGCyvmwQmBy2Uww4x9f71GEl4Z8U=; b=Mg/RbhUVcZGhk3B4kiPG6h6dz17W5H5ueFa5gOuRh+kIavUPChXHQQF2z9BGrQjl6p sGYAWPyAe9wBi8wqRh+gG8wk7L6G5GSB08lOZzxonYm0iLiMsQRKWD1sXCYtbc9kYyy7 qoWN/kOXT3LFzVcQP6iW19vf2RLrU3/AKguLu4xopTHkHDFLaJobQRKQly95RjMRayzw tfoDZSyPeh0hYGIbz7CrunxPij1L5+Hs6WzJe96ZutTMrXsNAMiLG7WOdQhVdwmi8wt3 RepZDKFBIXbrF00mwA++Fo9rN7gN/9ytRtV2SzNXhKyZHotN5OUdKTpyqfH8RDa7lBso hUeA== X-Gm-Message-State: APjAAAW6os73kphcZ9vPl7WjZkGlwV/N05JBRAEWjDkZr+CaNsyn2Bf3 BYD1DOBcvF5n2r7iDZiVUUk3uQ== X-Google-Smtp-Source: APXvYqzkOuhDdUWLlgA6SbWta6SkUoWU+Z0M/BpBE4YDjY9UHet/ggDjHI1KlYIoeSDu6bnRUGp2SA== X-Received: by 2002:a17:902:9a06:: with SMTP id v6mr25829128plp.221.1570489081140; Mon, 07 Oct 2019 15:58:01 -0700 (PDT) Received: from localhost ([2601:602:9200:a1a5:ad34:3a95:9a31:e6bb]) by smtp.gmail.com with ESMTPSA id f62sm16453675pfg.74.2019.10.07.15.57.59 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 07 Oct 2019 15:58:00 -0700 (PDT) From: Kevin Hilman To: Martin Blumenstingl , Anand Moon Cc: Rob Herring , Mark Rutland , Jerome Brunet , Neil Armstrong , Catalin Marinas , Will Deacon , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFCv1 5/5] arm64/ARM: configs: Change CONFIG_PWM_MESON from m to y In-Reply-To: References: <20191007131649.1768-1-linux.amoon@gmail.com> <20191007131649.1768-6-linux.amoon@gmail.com> Date: Mon, 07 Oct 2019 15:57:59 -0700 Message-ID: <7hsgo4cgeg.fsf@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Martin Blumenstingl writes: > On Mon, Oct 7, 2019 at 3:17 PM Anand Moon wrote: > [...] >> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig >> index c9a867ac32d4..72f6a7dca0d6 100644 >> --- a/arch/arm64/configs/defconfig >> +++ b/arch/arm64/configs/defconfig >> @@ -774,7 +774,7 @@ CONFIG_MPL3115=m >> CONFIG_PWM=y >> CONFIG_PWM_BCM2835=m >> CONFIG_PWM_CROS_EC=m >> -CONFIG_PWM_MESON=m >> +CONFIG_PWM_MESON=y > > some time ago I submitted a similar patch for the 32-bit SoCs > it turned that that pwm-meson can be built as module because the > kernel will run without CPU DVFS as long as the clock and regulator > drivers are returning -EPROBE_DEFER (-517) On 64-bit SoCs, the kernel boots with PWM as a module also, but DVFS only works sometimes, and making it built-in fixes the problem. Actually, it doesn't fix, it just hides the problem, which is likely a race or timeout happening during deferred probing. > did you check whether there's some other problem like some unused > clock which is being disabled at that moment? > I've been hunting weird problems in the past where it turned out that > changing kernel config bits changed the boot timing - that masked the > original problem Right, I would definitely prefer to not make this built-in without a lot more information to *why* this is needed. In figuring that out, we'll probably find the race/timeout that's the root cause. Kevin