linux-kernel - [PATCH] iio/pressure/mpl3115: Improve unlocking of a mutex in mpl3115_trigger

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Date:   Thu, 26 Oct 2017 16:23:45 +0200
From:   SF Markus Elfring <elfring@...rs.sourceforge.net>
To:     linux-iio@...r.kernel.org, Hartmut Knaack <knaack.h@....de>,
        Jonathan Cameron <jic23@...nel.org>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        Peter Rosin <peda@...ntia.se>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org
Subject: [PATCH] iio/pressure/mpl3115: Improve unlocking of a mutex in
 mpl3115_trigger_handler()

From: Markus Elfring <elfring@...rs.sourceforge.net>
Date: Thu, 26 Oct 2017 16:10:46 +0200

Adjust jump targets so that a call of the function "mutex_unlock" is stored
at the end of this function implementation.
Replace three calls by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
---
 drivers/iio/pressure/mpl3115.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/pressure/mpl3115.c b/drivers/iio/pressure/mpl3115.c
index 7537547fb7ee..f39e6f42a9c0 100644
--- a/drivers/iio/pressure/mpl3115.c
+++ b/drivers/iio/pressure/mpl3115.c
@@ -152,38 +152,36 @@ static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
 
 	mutex_lock(&data->lock);
 	ret = mpl3115_request(data);
-	if (ret < 0) {
-		mutex_unlock(&data->lock);
-		goto done;
-	}
+	if (ret < 0)
+		goto unlock;
 
 	memset(buffer, 0, sizeof(buffer));
 	if (test_bit(0, indio_dev->active_scan_mask)) {
 		ret = i2c_smbus_read_i2c_block_data(data->client,
 			MPL3115_OUT_PRESS, 3, &buffer[pos]);
-		if (ret < 0) {
-			mutex_unlock(&data->lock);
-			goto done;
-		}
+		if (ret < 0)
+			goto unlock;
+
 		pos += 4;
 	}
 
 	if (test_bit(1, indio_dev->active_scan_mask)) {
 		ret = i2c_smbus_read_i2c_block_data(data->client,
 			MPL3115_OUT_TEMP, 2, &buffer[pos]);
-		if (ret < 0) {
-			mutex_unlock(&data->lock);
-			goto done;
-		}
+		if (ret < 0)
+			goto unlock;
 	}
 	mutex_unlock(&data->lock);
 
 	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
 		iio_get_time_ns(indio_dev));
-
-done:
+notify_trigger:
 	iio_trigger_notify_done(indio_dev->trig);
 	return IRQ_HANDLED;
+
+unlock:
+	mutex_unlock(&data->lock);
+	goto notify_trigger;
 }
 
 static const struct iio_chan_spec mpl3115_channels[] = {
-- 
2.14.3