[PATCH v2 resend] iio: imu: bmi160: add mutex_lock for avoiding race

From: Guoqing Chi <chi962464zy@163.com>
To: trix@redhat.com
Cc: linux-iio@vger.kernel.org, jic23@kernel.org, huyue2@yulong.com,
	linux-kernel@vger.kernel.org, zhangwen@yulong.com,
	chiguoqing@yulong.com, chiguoqing <chi962464zy@163.com>
Subject: [PATCH v2 resend] iio: imu: bmi160: add mutex_lock for avoiding race
Date: Mon, 25 Jan 2021 09:53:44 +0800	[thread overview]
Message-ID: <20210125015344.106-1-chi962464zy@163.com> (raw)

From: chiguoqing <chi962464zy@163.com>

Adding mutex_lock, when read and write reg need to use this lock to
avoid race.

Signed-off-by: Guoqing Chi <chiguoqing@yulong.com>
Reviewed-by: Tom Rix <trix@redhat.com>
---
v2:Follow write function to fix read function.
Adding mutex init in core probe function.
Adding break in switch case at read and write function.

 drivers/iio/imu/bmi160/bmi160.h      |  2 ++
 drivers/iio/imu/bmi160/bmi160_core.c | 34 +++++++++++++++++++---------
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/imu/bmi160/bmi160.h b/drivers/iio/imu/bmi160/bmi160.h
index 32c2ea2d7112..0c189a8b5b53 100644
--- a/drivers/iio/imu/bmi160/bmi160.h
+++ b/drivers/iio/imu/bmi160/bmi160.h
@@ -3,9 +3,11 @@
 #define BMI160_H_
 
 #include <linux/iio/iio.h>
+#include <linux/mutex.h>
 #include <linux/regulator/consumer.h>
 
 struct bmi160_data {
+	struct mutex lock;
 	struct regmap *regmap;
 	struct iio_trigger *trig;
 	struct regulator_bulk_data supplies[2];
diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c
index 290b5ef83f77..e303378f4841 100644
--- a/drivers/iio/imu/bmi160/bmi160_core.c
+++ b/drivers/iio/imu/bmi160/bmi160_core.c
@@ -452,26 +452,32 @@ static int bmi160_read_raw(struct iio_dev *indio_dev,
 	int ret;
 	struct bmi160_data *data = iio_priv(indio_dev);
 
+	mutex_lock(&data->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		ret = bmi160_get_data(data, chan->type, chan->channel2, val);
-		if (ret)
-			return ret;
-		return IIO_VAL_INT;
+		if (!ret)
+			ret = IIO_VAL_INT;
+		break;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
 		ret = bmi160_get_scale(data,
 				       bmi160_to_sensor(chan->type), val2);
-		return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
+		if (!ret)
+			ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret = bmi160_get_odr(data, bmi160_to_sensor(chan->type),
 				     val, val2);
-		return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
+		if (!ret)
+			ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
 	}
+	mutex_unlock(&data->lock);
 
-	return 0;
+	return ret;
 }
 
 static int bmi160_write_raw(struct iio_dev *indio_dev,
@@ -479,19 +485,24 @@ static int bmi160_write_raw(struct iio_dev *indio_dev,
 			    int val, int val2, long mask)
 {
 	struct bmi160_data *data = iio_priv(indio_dev);
+	int result;
 
+	mutex_lock(&data->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
-		return bmi160_set_scale(data,
+		result = bmi160_set_scale(data,
 					bmi160_to_sensor(chan->type), val2);
+		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		return bmi160_set_odr(data, bmi160_to_sensor(chan->type),
+		result = bmi160_set_odr(data, bmi160_to_sensor(chan->type),
 				      val, val2);
+		break;
 	default:
-		return -EINVAL;
+		result = -EINVAL;
 	}
+	mutex_unlock(&data->lock);
 
-	return 0;
+	return result;
 }
 
 static
@@ -838,6 +849,7 @@ int bmi160_core_probe(struct device *dev, struct regmap *regmap,
 		return -ENOMEM;
 
 	data = iio_priv(indio_dev);
+	mutex_init(&data->lock);
 	dev_set_drvdata(dev, indio_dev);
 	data->regmap = regmap;
 
-- 
2.17.1


