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From:   Herve Codina <herve.codina@bootlin.com>
To:     Herve Codina <herve.codina@bootlin.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: [PATCH v5 03/13] iio: inkern: Check error explicitly in iio_channel_read_max()
Date:   Thu, 15 Jun 2023 17:26:21 +0200
Message-Id: <20230615152631.224529-4-herve.codina@bootlin.com>
In-Reply-To: <20230615152631.224529-1-herve.codina@bootlin.com>
References: <20230615152631.224529-1-herve.codina@bootlin.com>
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The current implementation returns the error code as part of the
default switch case.
This can lead to returning an incorrect positive value in case of
iio_avail_type enum entries evolution.

In order to avoid this case, be more strict in error checking.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 drivers/iio/inkern.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 872fd5c24147..f738db9a0c04 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -858,6 +858,9 @@ static int iio_channel_read_max(struct iio_channel *chan,
 		val2 = &unused;
 
 	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
+	if (ret < 0)
+		return ret;
+
 	switch (ret) {
 	case IIO_AVAIL_RANGE:
 		switch (*type) {
@@ -888,7 +891,7 @@ static int iio_channel_read_max(struct iio_channel *chan,
 		return 0;
 
 	default:
-		return ret;
+		return -EINVAL;
 	}
 }
 
-- 
2.40.1