From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE,T_DKIMWL_WL_HIGH autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id DE3987D2F0 for ; Wed, 5 Jun 2019 08:48:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726685AbfFEIsR (ORCPT ); Wed, 5 Jun 2019 04:48:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:56040 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726502AbfFEIsR (ORCPT ); Wed, 5 Jun 2019 04:48:17 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2F55E20717; Wed, 5 Jun 2019 08:48:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559724495; bh=HyxdwhePu475mlk6ZfWQFJ1e0/vC/dpndsU7nAlUZkc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Zo1x6OLHg7ET5lmotN15Plt/iC3RZc8twLZ78TLkoAHz8E0RHd81au12XeM2b4ar/ 0zaMcRqecxtqZrAUbTAd/xRBdX0LTZzvuVWi3gj5Z4efttBdlC/wr8OO5FctuOXcMb heeLtgj+9SHL6/1/MFwMO5Ii0OrKq6ASMKgUOALc= Date: Wed, 5 Jun 2019 10:48:13 +0200 From: Greg Kroah-Hartman To: Lee Jones Cc: Guenter Roeck , Ezequiel Garcia , Enric Balletbo i Serra , linux-kernel , Gwendal Grignou , Guenter Roeck , Benson Leung , kernel@collabora.com, Dmitry Torokhov , Gustavo Pimentel , Randy Dunlap , Lorenzo Pieralisi , linux-doc@vger.kernel.org, Enno Luebbers , Guido Kiener , Thomas Gleixner , Kishon Vijay Abraham I , Jonathan Corbet , Wu Hao , Kate Stewart , Tycho Andersen , Gerd Hoffmann , Jilayne Lovejoy Subject: Re: [PATCH 03/10] mfd / platform: cros_ec: Miscellaneous character device to talk with the EC Message-ID: <20190605084813.GA26984@kroah.com> References: <20190604152019.16100-1-enric.balletbo@collabora.com> <20190604152019.16100-4-enric.balletbo@collabora.com> <20190604155228.GB9981@kroah.com> <20190604183527.GA20098@kroah.com> <20190604185953.GA2061@kroah.com> <20190605064839.GH4797@dell> <20190605080241.GC9693@kroah.com> <20190605084002.GP4797@dell> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190605084002.GP4797@dell> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Jun 05, 2019 at 09:40:02AM +0100, Lee Jones wrote: > On Wed, 05 Jun 2019, Greg Kroah-Hartman wrote: > > > On Wed, Jun 05, 2019 at 07:48:39AM +0100, Lee Jones wrote: > > > On Tue, 04 Jun 2019, Greg Kroah-Hartman wrote: > > > > On Tue, Jun 04, 2019 at 11:39:21AM -0700, Guenter Roeck wrote: > > > > > On Tue, Jun 4, 2019 at 11:35 AM Greg Kroah-Hartman > > > > > wrote: > > > > > > > > > > > > On Tue, Jun 04, 2019 at 01:58:38PM -0300, Ezequiel Garcia wrote: > > > > > > > Hey Greg, > > > > > > > > > > > > > > > > + dev_info(&pdev->dev, "Created misc device /dev/%s\n", > > > > > > > > > + data->misc.name); > > > > > > > > > > > > > > > > No need to be noisy, if all goes well, your code should be quiet. > > > > > > > > > > > > > > > > > > > > > > I sometimes wonder about this being noise or not, so I will slightly > > > > > > > hijack this thread for this discussion. > > > > > > > > > > > > > > >From a kernel developer point-of-view, or even from a platform > > > > > > > developer or user with a debugging hat point-of-view, having > > > > > > > a "device created" or "device registered" message is often very useful. > > > > > > > > > > > > For you, yes. For someone with 30000 devices attached to their system, > > > > > > it is not, and causes booting to take longer than it should be. > > > > > > Who has 30,000 devices attached to their systems? > > > > More than you might imagine. > > > > > I would argue that > > > in these special corner-cases, they should knock the log-level *down* > > > a notch. For the rest of us who run normal platforms, an extra second > > > of boot time renders a more forthcoming/useful system than if each of > > > our devices initialised silently. > > > > > > Personally I like to know what devices I have on my system, and the > > > kernel log is the first place I look. As far as I'm concerned, for > > > the most part, if it's not in the kernel log, I don't have it. > > > > Then you "do not have" lots of devices, as we have been removing these > > messages for a number of years now :) > > > > > "Oh wow, I didn't know I had XXX functionality on this platform." > > > > > > In my real job, I am currently enabling some newly released AArch64 > > > based laptops for booting with ACPI. I must have wasted a day whilst > > > enabling some of the devices the system relies upon, just to find > > > out that 90% of them were actually probing semi-fine (at least probe() > > > was succeeding), just silently. *grumble* > > > > Yup, that's normal. If you want to see what devices are in the system, > > look in /sys/devices/ as that is what it is for, not the kernel log. > > My guess is that less than 1% of Linux users use /sys/devices in this > way. It's a very unfriendly interface. Besides, when enabling a new > platform, access to sysfs comes too far down the line to be useful in > the majority of cases. `lshw` is your friend :)