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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 09D38C28CC6 for ; Wed, 5 Jun 2019 08:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D513E206BA for ; Wed, 5 Jun 2019 08:23:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="UqEtGE+i" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726729AbfFEIXi (ORCPT ); Wed, 5 Jun 2019 04:23:38 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:39067 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726697AbfFEIXc (ORCPT ); Wed, 5 Jun 2019 04:23:32 -0400 Received: by mail-wm1-f66.google.com with SMTP id z23so1286025wma.4 for ; Wed, 05 Jun 2019 01:23:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=KB8B36tEhg7g9/5o0/vbeuwsLyG7Xckc2xGFAP6zc6U=; b=UqEtGE+iGLEv5a8+dhYUt/TpItZVF7YutlO2qMc8O+pmYdpG03c90Q518SSLMajSWX f40/pwGMGtZCV4kbgbWm0h1VBrWAX3B+JhWGEJIOiQNTAxpC6a0767jdQXd2NJSczqCn Rs9t3jhO9MHLwTczbKWos+GUz2T/hyu1HSM1lGIRsKGEHcChMtA2FgZodaGlisIRYavh 73kSTJkBWr2HxbeHeJcnCdjbOB6Pjxpscko+f36AOaVmL1y652yazuLNBrB8XoqUiqb2 YrzeXXMfW0z4uJDCH9Px7WTFnuY7s4VmVe8yBfYOi4IiJpYCUjXKiUTI5F+B+Q1eyAVc Ts+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=KB8B36tEhg7g9/5o0/vbeuwsLyG7Xckc2xGFAP6zc6U=; b=LdVOYMmEDOmET04rjJIDhrlx6lDBr+158hDWiETUly/zrtoPUMnXafNaMO8lpWr8jA BRz+u+4xwhzsVH4mSlQn6xkN1EkoOilpg+3dYnRnauG/ps6IQzZSDR8L8H0K9JmUpec/ CVjjjJWIrVh7mQbY5MlXWFwJH0N2jK3IzwtFlYFbxHJ95cReI12YOMIyUUUppcGGKL2+ gVzFoOhgfMwTfxx7n50FM1RplTYJZAjwl/YfJySPvH/S5l2FeGS06PRL7LSUu2+N6FCz i7noH9zdXxpISpDNnUZePkJMO3ANgeME/9/mRVvKlRvpFHoT0YJOwVxpmZpT80VmNY0s 1zRA== X-Gm-Message-State: APjAAAW0ppJyYO49tkWQUod9o6+b4eT5YMXF6fB87846JdevNtb0gE/Y L11oCbWppufv7mnPqU1Kk3ofrw== X-Google-Smtp-Source: APXvYqyn7r2Og6MqHzF9tB1GS7hQSk2g0XHprHTvLKG654EdQDiLEPjf16VyH9JzBnK035IC2hV9qw== X-Received: by 2002:a1c:f311:: with SMTP id q17mr20555885wmq.2.1559723010516; Wed, 05 Jun 2019 01:23:30 -0700 (PDT) Received: from dell ([2.27.167.43]) by smtp.gmail.com with ESMTPSA id d2sm14874801wmb.9.2019.06.05.01.23.29 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 05 Jun 2019 01:23:29 -0700 (PDT) Date: Wed, 5 Jun 2019 09:23:27 +0100 From: Lee Jones To: Ard Biesheuvel Cc: Bjorn Andersson , balbi@kernel.org, wsa+renesas@sang-engineering.com, Greg Kroah-Hartman , Linus Walleij , linux-usb , Linux Kernel Mailing List , David Brown , alokc@codeaurora.org, kramasub@codeaurora.org, linux-i2c , "open list:GPIO SUBSYSTEM" , linux-arm-msm , Andy Gross , Jeffrey Hugo , linux-arm-kernel Subject: Re: [PATCH 2/8] i2c: i2c-qcom-geni: Signify successful driver probe Message-ID: <20190605082327.GN4797@dell> References: <20190604104455.8877-1-lee.jones@linaro.org> <20190604104455.8877-2-lee.jones@linaro.org> <20190605062020.GL22737@tuxbook-pro> <20190605071625.GK4797@dell> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, 05 Jun 2019, Ard Biesheuvel wrote: > On Wed, 5 Jun 2019 at 09:16, Lee Jones wrote: > > > > On Tue, 04 Jun 2019, Bjorn Andersson wrote: > > > > > On Tue 04 Jun 03:44 PDT 2019, Lee Jones wrote: > > > > > > > The Qualcomm Geni I2C driver currently probes silently which can be > > > > confusing when debugging potential issues. Add a low level (INFO) > > > > print when each I2C controller is successfully initially set-up. > > > > > > > > Signed-off-by: Lee Jones > > > > --- > > > > drivers/i2c/busses/i2c-qcom-geni.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c > > > > index 0fa93b448e8d..e27466d77767 100644 > > > > --- a/drivers/i2c/busses/i2c-qcom-geni.c > > > > +++ b/drivers/i2c/busses/i2c-qcom-geni.c > > > > @@ -598,6 +598,8 @@ static int geni_i2c_probe(struct platform_device *pdev) > > > > return ret; > > > > } > > > > > > > > + dev_info(&pdev->dev, "Geni-I2C adaptor successfully added\n"); > > > > + > > > > > > I would prefer that we do not add such prints, as it would be to accept > > > the downstream behaviour of spamming the log to the point where no one > > > will ever look through it. > > > > We should be able to find a middle ground. Spamming the log with all > > sorts of device specific information/debug is obviously not > > constructive, but a single liner to advertise that an important > > device/controller has been successfully initialised is more helpful > > than it is hinderous. > > > > This print was added due to the silent initialisation costing me > > several hours of debugging ACPI device/driver code (albeit learning a > > lot about ACPI as I go) just to find out that it was already doing the > > right thing - just very quietly. > > > > I agree. > > There are numerous EHCI drivers IIRC which, if compiled in, > unconditionally print some blurb, whether you have the hardware or > not, which is pretty annoying. > > In this case, however, having a single line per successfully probed > device (containing the dev_name and perhaps the MMIO base address or > some other identifying feature) is pretty useful, and shouldn't be > regarded as log spamming imo. dev_info() honours the 'quiet' kernel > command line parameter, and so you will only see the message if you > actually look at the log. +999 This is exactly as I see it. If people want a quiet log/fast boot-up times, they can request it. Otherwise, it's far more useful to trade a second or two for important information such as which devices are present/enabled on a platform. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog