linux-kernel - [PATCH v2] rtc: s3c: Don't print an error on probe deferral

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Message-Id: <1457987157-1177-1-git-send-email-javier@osg.samsung.com>
Date:	Mon, 14 Mar 2016 17:25:57 -0300
From:	Javier Martinez Canillas <javier@....samsung.com>
To:	linux-kernel@...r.kernel.org
Cc:	Joe Perches <joe@...ches.com>,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
	linux-samsung-soc@...r.kernel.org,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	rtc-linux@...glegroups.com,
	Javier Martinez Canillas <javier@....samsung.com>
Subject: [PATCH v2] rtc: s3c: Don't print an error on probe deferral

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.

Signed-off-by: Javier Martinez Canillas <javier@....samsung.com>

---

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..4a3a8eb35234 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 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 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);
 	}
-- 
2.5.0