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From:   =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>
To:     Matt Mackall <mpm@selenic.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>
Cc:     Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, kernel@pengutronix.de
Subject: [PATCH] hwrng: meson - Improve error handling for core clock
Date:   Tue, 14 Sep 2021 16:24:28 +0200
Message-Id: <20210914142428.57099-1-u.kleine-koenig@pengutronix.de>
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-ENOENT (ie. "there is no clock") is fine to ignore for an optional
clock, other values are not supposed to be ignored and should be
escalated to the caller (e.g. -EPROBE_DEFER). Ignore -ENOENT by using
devm_clk_get_optional().

While touching this code also add an error message for the fatal errors.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/char/hw_random/meson-rng.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
index e446236e81f2..9f3e2eb8011d 100644
--- a/drivers/char/hw_random/meson-rng.c
+++ b/drivers/char/hw_random/meson-rng.c
@@ -54,9 +54,15 @@ static int meson_rng_probe(struct platform_device *pdev)
 	if (IS_ERR(data->base))
 		return PTR_ERR(data->base);
 
-	data->core_clk = devm_clk_get(dev, "core");
-	if (IS_ERR(data->core_clk))
-		data->core_clk = NULL;
+	data->core_clk = devm_clk_get_optional(dev, "core");
+	if (IS_ERR(data->core_clk)) {
+		ret = PTR_ERR(data->core_clk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get core clock: %pe\n",
+				data->core_clk);
+
+		return ret;
+	}
 
 	if (data->core_clk) {
 		ret = clk_prepare_enable(data->core_clk);
-- 
2.30.2