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 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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9935CC47404 for ; Mon, 7 Oct 2019 22:58:15 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6ABA020867 for ; Mon, 7 Oct 2019 22:58:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="H4eNZrMd"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="A94WXkxS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6ABA020867 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=cpIGwrtA+SydarNeuXIBeCjhoZwqWJhKz2RUsRpEsHE=; b=H4eNZrMdcqX/18 1sec8FGhRUBrW93h5f3PvjSRwSr66rKJK5j+w9/pb4zZoG1zI+nKw+UL6/puimDJbdFQYRiQcMYSk qBnB1OqqxVcExNq3Kf1KgkVURkU/eQ+3pka9q6rupkWzYPI2lCiMm8iAkW9XY/wyrJKpSBdz3RjJy q5+kk7af7vAl+csJXuy+RogSZmxRdIixumgZwdN7gaxXkAFPJ8Wjkg25j3SOfHN7upAT1lPA99lZX zTjhZWwKFDfI27dWfhjUI6D0WnJ3mI1+WNivelH+cfyFtg7ypaE3QltyITqSxcUIO/2IGtEA9U49f IVchhPkwo7cQ9NW+PZHg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHbxA-0006NQ-NG; Mon, 07 Oct 2019 22:58:08 +0000 Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHbx5-0006Lj-Sm for linux-arm-kernel@lists.infradead.org; Mon, 07 Oct 2019 22:58:05 +0000 Received: by mail-pl1-x641.google.com with SMTP id d22so7589637pls.0 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=nnb8zubXJ0srD5jQA8bAo4rTBKc1nWQYDU7QirPx/+1bMo4L3NOq2u1QuPF6iWw3FM xuO3BuNwoNez8G3Ayf10Bfo2w1ts91BJ57mgTx8/GHCIS4Wn55CVL+ULPP5h853rmAm+ 9AitLzxSSd87/LBrGdHZs1EHmFaMx5cbzt7UiUhO96Z0OoplvMkS2Bo6Q5UbZVhuZv3d lWdiV74QRq2XTOop/tfDtAuXGWkNsfo5kY2pn8hwBnyWr0iGfO9kmhP8Tsc9HGU9jD0D NbVhz8mkys0Cz6BKCfL72yYH8vITWRvFjnlx3HnMa6F63SE24Oc2y2EsF7nvStYDQAKW GbZQ== X-Gm-Message-State: APjAAAVBIvDibKbnvAFBAH5eHE+EduCTTTdCKy51cnHNN9VTjt+OeNbQ cBiRfsKBc6kvv3rs7tgxO12yBA== 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191007_155803_981726_7D87F1CB X-CRM114-Status: GOOD ( 14.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, Neil Armstrong , Catalin Marinas , linux-kernel@vger.kernel.org, Rob Herring , linux-amlogic@lists.infradead.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Jerome Brunet Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E9789ECE58C for ; Mon, 7 Oct 2019 22:58:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BB54B20867 for ; Mon, 7 Oct 2019 22:58:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BNXwonve"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="A94WXkxS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB54B20867 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Dh0J8Bg9jC9q1nkf1VIroDa4SD/6MC0h2WZUWHwv23M=; b=BNXwonvekvOvLo I4+mCyhIf9JuaWnb/6pfvH4WgB0ZJWWsG1cOi/WxY/R6izjq2HljPcxuOnBtoSOg0PYsM/KGxVum9 XUwiIPsZfm8jEsFbFXJpg554RpikQv3y8c2IF9h3zasFzjqdW6PVljtlPtvf03JDfjQMMXDvKC9l/ +bMAztY6rNCH/qlOq+oQx2oSR/RBWyWK/BI3W7NWIm3Wm0z6H+s5jJDuCOulb+GBOibTF+0kWaPNA MQOrKObTgPdM8xNdeht9OpvH52RAzAQ3KmDUprC1lpseKXJgki3Wq5HIbC/s3Ua6Eh6qJh6hYyjSN sAB5lHO4/R3F4WfNd+yQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHbx9-0006Mr-EU; Mon, 07 Oct 2019 22:58:07 +0000 Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHbx5-0006Li-Sn for linux-amlogic@lists.infradead.org; Mon, 07 Oct 2019 22:58:05 +0000 Received: by mail-pl1-x641.google.com with SMTP id j11so7580945plk.3 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=tLTD1AsVFjXn70MhFzb9uPZ3TtNLj9sLUdWWk6HWScH/DBOnjDOAlqzjQR0DMeVdlI YyagMWNYxVEBy0wCtrvBv79Jkb4TW28E8WyGOu+i2nCmTBzXFOAEZqR1oCdzCafzPyte HxHo4WWdGr4sYjkztibajR6VNETvjzfUnCwovs5FTbAs/M2kBqdfrTPbPARTtxE/5drA Lu5UDGsWqVmdUv5oQMTv71YvtH6w9xyDNA2p8AFhCMF2YlmJ9SkD7JzdA2HnJjVf0wEk R21sGsIVauMCsVws8Aq3g0UZwRnBlPruQgM2S+BDXwV8Ve7ChoEb/t42Aur82Tgpp0VA sN7Q== X-Gm-Message-State: APjAAAXo1C3xqDNWpu2JxdUpwRTC5YaqI1zaYyBsGdsWafOugFu+NbwL 5O+UYtKg83eI7NpidOsBD/63wg== 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191007_155803_981374_DAB9FF3A X-CRM114-Status: GOOD ( 12.71 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, Neil Armstrong , Catalin Marinas , linux-kernel@vger.kernel.org, Rob Herring , linux-amlogic@lists.infradead.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Jerome Brunet Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.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 _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic