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

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
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 <elfr...@users.sourceforge.net>
---
 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