[PATCH] iio/accel/stk8312: Improve unlocking of a mutex in two functions

From: SF Markus Elfring
Date: Wed Oct 25 2017 - 14:55:49 EST


From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 25 Oct 2017 20:46:18 +0200

* Adjust jump targets so that a call of the function "mutex_unlock"
is mostly stored at the end of these function implementations.

* Replace four calls by goto statements.

* Adjust condition checks.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/iio/accel/stk8312.c | 35 ++++++++++++++++++-----------------
1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c
index cacc0da2f874..5275ab886e39 100644
--- a/drivers/iio/accel/stk8312.c
+++ b/drivers/iio/accel/stk8312.c
@@ -344,24 +344,24 @@ static int stk8312_read_raw(struct iio_dev *indio_dev,
return -EBUSY;
mutex_lock(&data->lock);
ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
- if (ret < 0) {
- mutex_unlock(&data->lock);
- return ret;
- }
+ if (ret)
+ goto unlock;
+
ret = stk8312_read_accel(data, chan->address);
if (ret < 0) {
stk8312_set_mode(data,
data->mode & (~STK8312_MODE_ACTIVE));
- mutex_unlock(&data->lock);
- return ret;
+ goto unlock;
}
*val = sign_extend32(ret, 7);
ret = stk8312_set_mode(data,
data->mode & (~STK8312_MODE_ACTIVE));
+unlock:
mutex_unlock(&data->lock);
- if (ret < 0)
- return ret;
- return IIO_VAL_INT;
+ if (!ret)
+ ret = IIO_VAL_INT;
+
+ return ret;
case IIO_CHAN_INFO_SCALE:
*val = stk8312_scale_table[data->range - 1][0];
*val2 = stk8312_scale_table[data->range - 1][1];
@@ -444,17 +444,15 @@ static irqreturn_t stk8312_trigger_handler(int irq, void *p)
data->buffer);
if (ret < STK8312_ALL_CHANNEL_SIZE) {
dev_err(&data->client->dev, "register read failed\n");
- mutex_unlock(&data->lock);
- goto err;
+ goto unlock_after_failure;
}
} else {
for_each_set_bit(bit, indio_dev->active_scan_mask,
indio_dev->masklength) {
ret = stk8312_read_accel(data, bit);
- if (ret < 0) {
- mutex_unlock(&data->lock);
- goto err;
- }
+ if (ret < 0)
+ goto unlock_after_failure;
+
data->buffer[i++] = ret;
}
}
@@ -462,10 +460,13 @@ static irqreturn_t stk8312_trigger_handler(int irq, void *p)

iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
pf->timestamp);
-err:
+notify_trigger:
iio_trigger_notify_done(indio_dev->trig);
-
return IRQ_HANDLED;
+
+unlock_after_failure:
+ mutex_unlock(&data->lock);
+ goto notify_trigger;
}

static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
--
2.14.3