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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org, "John Syne" <john3909@gmail.com>,
        "Jonathan Cameron" <Jonathan.Cameron@huawei.com>,
        "John Syne" <rodrigosiqueiramelo@gmail.com>
Date:   Sun, 11 Nov 2018 19:49:05 +0000
Message-ID: <lsq.1541965745.384667038@decadent.org.uk>
Subject: [PATCH 3.16 015/366] staging:iio:ade7854: Fix error handling on
 read/write
In-Reply-To: <lsq.1541965744.387173642@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: John Syne <rodrigosiqueiramelo@gmail.com>

commit 4297b23d927fa5265378f4a71372ecef3c33023a upstream.

The original code does not correctly handle the error related to I2C
read and write. This patch fixes the error handling related to all
read/write functions for I2C.

Signed-off-by: John Syne <john3909@gmail.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Fixes: 8d97a5877 ("staging: iio: meter: new driver for ADE7754 devices")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/staging/iio/meter/ade7854-i2c.c | 24 ++++++++++++------------
 drivers/staging/iio/meter/ade7854.c     | 10 +++++-----
 2 files changed, 17 insertions(+), 17 deletions(-)

--- a/drivers/staging/iio/meter/ade7854-i2c.c
+++ b/drivers/staging/iio/meter/ade7854-i2c.c
@@ -31,7 +31,7 @@ static int ade7854_i2c_write_reg_8(struc
 	ret = i2c_master_send(st->i2c, st->tx, 3);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_write_reg_16(struct device *dev,
@@ -51,7 +51,7 @@ static int ade7854_i2c_write_reg_16(stru
 	ret = i2c_master_send(st->i2c, st->tx, 4);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_write_reg_24(struct device *dev,
@@ -72,7 +72,7 @@ static int ade7854_i2c_write_reg_24(stru
 	ret = i2c_master_send(st->i2c, st->tx, 5);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_write_reg_32(struct device *dev,
@@ -94,7 +94,7 @@ static int ade7854_i2c_write_reg_32(stru
 	ret = i2c_master_send(st->i2c, st->tx, 6);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_read_reg_8(struct device *dev,
@@ -110,11 +110,11 @@ static int ade7854_i2c_read_reg_8(struct
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 1);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = st->rx[0];
@@ -136,11 +136,11 @@ static int ade7854_i2c_read_reg_16(struc
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = (st->rx[0] << 8) | st->rx[1];
@@ -162,11 +162,11 @@ static int ade7854_i2c_read_reg_24(struc
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 3);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = (st->rx[0] << 16) | (st->rx[1] << 8) | st->rx[2];
@@ -188,11 +188,11 @@ static int ade7854_i2c_read_reg_32(struc
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 3);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = (st->rx[0] << 24) | (st->rx[1] << 16) | (st->rx[2] << 8) | st->rx[3];
--- a/drivers/staging/iio/meter/ade7854.c
+++ b/drivers/staging/iio/meter/ade7854.c
@@ -33,7 +33,7 @@ static ssize_t ade7854_read_8bit(struct
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
 	ret = st->read_reg_8(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -50,7 +50,7 @@ static ssize_t ade7854_read_16bit(struct
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
 	ret = st->read_reg_16(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -67,7 +67,7 @@ static ssize_t ade7854_read_24bit(struct
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
 	ret = st->read_reg_24(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -84,7 +84,7 @@ static ssize_t ade7854_read_32bit(struct
 	struct ade7854_state *st = iio_priv(indio_dev);
 
 	ret = st->read_reg_32(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -416,7 +416,7 @@ static int ade7854_set_irq(struct device
 	u32 irqen;
 
 	ret = st->read_reg_32(dev, ADE7854_MASK0, &irqen);
-	if (ret)
+	if (ret < 0)
 		goto error_ret;
 
 	if (enable)