From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailout1.w1.samsung.com (mailout1.w1.samsung.com. [210.118.77.11]) by gmr-mx.google.com with ESMTPS id tu5si2910432pab.2.2016.03.14.19.27.07 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 14 Mar 2016 19:27:07 -0700 (PDT) Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout1.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0O42000M66T2FA90@mailout1.w1.samsung.com> for rtc-linux@googlegroups.com; Tue, 15 Mar 2016 02:27:02 +0000 (GMT) Subject: [rtc-linux] Re: [PATCH v3] rtc: s3c: Don't print an error on probe deferral To: Javier Martinez Canillas , linux-kernel@vger.kernel.org References: <1458005918-7893-1-git-send-email-javier@osg.samsung.com> <56E76A57.7070104@samsung.com> <56E76C6F.5020803@osg.samsung.com> Cc: Joe Perches , Alexandre Belloni , linux-samsung-soc@vger.kernel.org, rtc-linux@googlegroups.com From: Krzysztof Kozlowski Message-id: <56E772F2.2030507@samsung.com> Date: Tue, 15 Mar 2016 11:26:58 +0900 MIME-version: 1.0 In-reply-to: <56E76C6F.5020803@osg.samsung.com> Content-type: text/plain; charset=UTF-8 Reply-To: rtc-linux@googlegroups.com List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , On 15.03.2016 10:59, Javier Martinez Canillas wrote: > Hello Krzysztof, > > On 03/14/2016 10:50 PM, Krzysztof Kozlowski wrote: >> On 15.03.2016 10:38, 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 a debug information. >>> >>> Signed-off-by: Javier Martinez Canillas >>> >>> --- >>> >>> Changes in v3: >>> - Change debug messages again as suggested by Joe Perches. >>> >>> Changes in v2: >>> - Improve debug messages as suggested by Joe Perches. >>> >>> drivers/rtc/rtc-s3c.c | 19 ++++++++++++++----- >>> 1 file changed, 14 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c >>> index ffb860d18701..d01ad7e8078e 100644 >>> --- 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 to missing rtc clk\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 to missing rtc src clk\n"); >>> clk_disable_unprepare(info->rtc_clk); >>> - return PTR_ERR(info->rtc_src_clk); >>> + return ret; >>> } >>> clk_prepare_enable(info->rtc_src_clk); >>> } >>> >> >> The error path starts looking complicated. This has now 4 indentation >> levels... >> > > Yeah, I don't think we can get rid of the 4 indentation levels since > the function already has 3 and a check for the errno code is needed. Probably handling of the clocks in the driver could be simplified a little bit (the if(needs_src_clk) appears in few places)... but this is out of scope for this patch. > >> I agree for removal of error in case of probe deferral because it might >> be misleading but I don't see much benefit of a debug message. >> > > But yes, we can at least get rid of the else statement. I don't have a > strong opinion about the debug information, I left it to avoid someone > to tell me that I was removing a useful log. Although dev_dbg doesn't harm... but isn't driver core printing debug message already? BR, Krzysztof -- -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscribe@googlegroups.com. For more options, visit https://groups.google.com/d/optout.