From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755060AbcCPLTv (ORCPT ); Wed, 16 Mar 2016 07:19:51 -0400 Received: from lists.s-osg.org ([54.187.51.154]:54081 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753912AbcCPLTt (ORCPT ); Wed, 16 Mar 2016 07:19:49 -0400 Subject: Re: [PATCH] regulator: Don't print error in devm_regulator_bulk_get() on -EPROBE_DEFER To: Mark Brown References: <1458074114-8088-1-git-send-email-javier@osg.samsung.com> <20160316095946.GR2566@sirena.org.uk> From: Javier Martinez Canillas Cc: linux-kernel@vger.kernel.org, Liam Girdwood Message-ID: <56E9414E.3030609@osg.samsung.com> Date: Wed, 16 Mar 2016 08:19:42 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160316095946.GR2566@sirena.org.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Mark, On 03/16/2016 06:59 AM, Mark Brown wrote: > On Tue, Mar 15, 2016 at 05:35:14PM -0300, Javier Martinez Canillas wrote: > >> The regulators may not be available just because their driver's probe was >> not executed and the regulators were not registered yet. So don't print an >> error in this case to avoid polluting the kernel log and confuse the users. > > We've been through this repeatedly - this is the case for all probe > deferrals and if we just don't print the errors at all then people won't > be able to tell if they've got a missing dependency. We need people to I wonder if we can use a dev_dbg() then so it will be printed at debug level. That way users can have that info if they want but not pollute the boot log. Basically I want to get rid of things like this: [ 1.438422] exynos-hdmi 14530000.hdmi: Failed to get supply 'vdd': -517 [ 1.443638] [drm:hdmi_probe] *ERROR* failed to get regulators [ 1.449326] [drm:hdmi_probe] *ERROR* hdmi_resources_init failed The HDMI driver probed correctly but looking at the log it seems that things failed so can mislead users not familiar with the probe deferral mechanism. > work on things like allowing the kernel to make use of the dependency > information it has to order probes more sensibly. > Agreed, I've seen Tomeu's patches and the following discussions. > Raphael had some ideas he was talking about at Kernel Summit for this, > Russell King also proposed just suppressing the errors until we're at > the last deferred probe run at the end of init. > Suppressing errors is a nice idea but will again lead to false positives when the drivers are built as a module AFAICT. Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America