From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755927AbcCNTbu (ORCPT ); Mon, 14 Mar 2016 15:31:50 -0400 Received: from lists.s-osg.org ([54.187.51.154]:53803 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755658AbcCNTbs (ORCPT ); Mon, 14 Mar 2016 15:31:48 -0400 Subject: Re: [PATCH] rtc: s3c: Don't print an error on probe deferral To: Joe Perches , linux-kernel@vger.kernel.org References: <1457982308-29848-1-git-send-email-javier@osg.samsung.com> <1457982675.11972.119.camel@perches.com> From: Javier Martinez Canillas Cc: Alexandre Belloni , linux-samsung-soc@vger.kernel.org, Krzysztof Kozlowski , rtc-linux@googlegroups.com Message-ID: <56E7119B.9060900@osg.samsung.com> Date: Mon, 14 Mar 2016 16:31:39 -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: <1457982675.11972.119.camel@perches.com> 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 Joe, Thanks a lot for your feedback. On 03/14/2016 04:11 PM, Joe Perches wrote: > On Mon, 2016-03-14 at 16:05 -0300, Javier Martinez Canillas wrote: >> The clock and source clock looked up by the driver may not be available >> just because the clock controller driver was not probed yet so printing >> an error in this case is not correct and only adds confusion to users. >> >> However, knowing that a driver's probe was deferred may be useful so it >> can be printed as debug information. > [] >> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c > [] >> @@ -501,18 +501,27 @@ static int s3c_rtc_probe(struct platform_device *pdev) >> >> info->rtc_clk = devm_clk_get(&pdev->dev, "rtc"); >> if (IS_ERR(info->rtc_clk)) { >> - dev_err(&pdev->dev, "failed to find rtc clock\n"); >> - return PTR_ERR(info->rtc_clk); >> + ret = PTR_ERR(info->rtc_clk); >> + if (ret != -EPROBE_DEFER) >> + dev_err(&pdev->dev, "failed to find rtc clock\n"); >> + else >> + dev_dbg(&pdev->dev, "probe deferred due rtc clock\n"); >> + return ret; >> } >> clk_prepare_enable(info->rtc_clk); >> >> if (info->data->needs_src_clk) { >> info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src"); >> if (IS_ERR(info->rtc_src_clk)) { >> - dev_err(&pdev->dev, >> - "failed to find rtc source clock\n"); >> + ret = PTR_ERR(info->rtc_src_clk); >> + if (ret != -EPROBE_DEFER) >> + dev_err(&pdev->dev, >> + "failed to find rtc source clock\n"); >> + else >> + dev_dbg(&pdev->dev, >> + "probe deferred due rtc source clock\n"); >> clk_disable_unprepare(info->rtc_clk); >> - return PTR_ERR(info->rtc_src_clk); >> + return ret; >> } >> clk_prepare_enable(info->rtc_src_clk); >> } > > Maybe the debug logging messages could be object->action like: > > rtc clock probe deferred > rtc source clock probe deferred > I found your suggested messages harder to read and more confusing. The action that happens is a probe function deferral and that is caused by a missing resource needed by the driver (clocks in this case). But your messages seems to imply that the probe deferred action happens to a clock, it sounds like "rtc clock disabled" and that's not correct. Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America