Re: [PATCH] iio/adc/nau7802: Improve unlocking of a mutex in nau7802_read_raw()

[Jonathan Cameron]

On Tue, 13 Mar 2018 20:56:25 +0100
SF Markus Elfring  wrote:

> From: Markus Elfring 
> Date: Tue, 13 Mar 2018 20:52:26 +0100
> 
> * Add a jump target so that a call of the function "mutex_unlock" is stored
>   only once in this function implementation.
> 
> * Replace two calls by goto statements.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring 
Similar to other cases, this non obvious error handling flow rather implies
that this block of code might work better as a utility function called from
the case statement.

> ---
>  drivers/iio/adc/nau7802.c | 15 +--
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iio/adc/nau7802.c b/drivers/iio/adc/nau7802.c
> index 8997e74a8847..68d06a492760 100644
> --- a/drivers/iio/adc/nau7802.c
> +++ b/drivers/iio/adc/nau7802.c
> @@ -303,10 +303,8 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
>*   - Channel 2 is value 1 in the CHS register
>*/
>   ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL2);
> - if (ret < 0) {
> - mutex_unlock(>lock);
> - return ret;
> - }
> + if (ret < 0)
> + goto unlock;
>  
>   if (((ret & NAU7802_CTRL2_CHS_BIT) && !chan->channel) ||
>   (!(ret & NAU7802_CTRL2_CHS_BIT) &&
> @@ -316,18 +314,15 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
>   NAU7802_REG_CTRL2,
>   NAU7802_CTRL2_CHS(chan->channel) |
>   NAU7802_CTRL2_CRS(st->sample_rate));
> -
> - if (ret < 0) {
> - mutex_unlock(>lock);
> - return ret;
> - }
> + if (ret < 0)
> + goto unlock;
>   }
>  
>   if (st->client->irq)
>   ret = nau7802_read_irq(indio_dev, chan, val);
>   else
>   ret = nau7802_read_poll(indio_dev, chan, val);
> -
> +unlock:
>   mutex_unlock(>lock);
blank line before simple returns.  It isn't a major enough part to be
worth the noise of adding them to existing code, but there is no reason
to take them out!

>   return ret;
>  

Re: [PATCH] iio/adc/nau7802: Improve unlocking of a mutex in nau7802_read_raw()

[Jonathan Cameron]

On Tue, 13 Mar 2018 20:56:25 +0100
SF Markus Elfring  wrote:

> From: Markus Elfring 
> Date: Tue, 13 Mar 2018 20:52:26 +0100
> 
> * Add a jump target so that a call of the function "mutex_unlock" is stored
>   only once in this function implementation.
> 
> * Replace two calls by goto statements.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring 
Similar to other cases, this non obvious error handling flow rather implies
that this block of code might work better as a utility function called from
the case statement.

> ---
>  drivers/iio/adc/nau7802.c | 15 +--
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iio/adc/nau7802.c b/drivers/iio/adc/nau7802.c
> index 8997e74a8847..68d06a492760 100644
> --- a/drivers/iio/adc/nau7802.c
> +++ b/drivers/iio/adc/nau7802.c
> @@ -303,10 +303,8 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
>*   - Channel 2 is value 1 in the CHS register
>*/
>   ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL2);
> - if (ret < 0) {
> - mutex_unlock(>lock);
> - return ret;
> - }
> + if (ret < 0)
> + goto unlock;
>  
>   if (((ret & NAU7802_CTRL2_CHS_BIT) && !chan->channel) ||
>   (!(ret & NAU7802_CTRL2_CHS_BIT) &&
> @@ -316,18 +314,15 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
>   NAU7802_REG_CTRL2,
>   NAU7802_CTRL2_CHS(chan->channel) |
>   NAU7802_CTRL2_CRS(st->sample_rate));
> -
> - if (ret < 0) {
> - mutex_unlock(>lock);
> - return ret;
> - }
> + if (ret < 0)
> + goto unlock;
>   }
>  
>   if (st->client->irq)
>   ret = nau7802_read_irq(indio_dev, chan, val);
>   else
>   ret = nau7802_read_poll(indio_dev, chan, val);
> -
> +unlock:
>   mutex_unlock(>lock);
blank line before simple returns.  It isn't a major enough part to be
worth the noise of adding them to existing code, but there is no reason
to take them out!

>   return ret;
>  

[PATCH] iio/adc/nau7802: Improve unlocking of a mutex in nau7802_read_raw()

[SF Markus Elfring]

From: Markus Elfring 
Date: Tue, 13 Mar 2018 20:52:26 +0100

* Add a jump target so that a call of the function "mutex_unlock" is stored
  only once in this function implementation.

* Replace two calls by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
---
 drivers/iio/adc/nau7802.c | 15 +--
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/nau7802.c b/drivers/iio/adc/nau7802.c
index 8997e74a8847..68d06a492760 100644
--- a/drivers/iio/adc/nau7802.c
+++ b/drivers/iio/adc/nau7802.c
@@ -303,10 +303,8 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
 *   - Channel 2 is value 1 in the CHS register
 */
ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL2);
-   if (ret < 0) {
-   mutex_unlock(>lock);
-   return ret;
-   }
+   if (ret < 0)
+   goto unlock;
 
if (((ret & NAU7802_CTRL2_CHS_BIT) && !chan->channel) ||
(!(ret & NAU7802_CTRL2_CHS_BIT) &&
@@ -316,18 +314,15 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
NAU7802_REG_CTRL2,
NAU7802_CTRL2_CHS(chan->channel) |
NAU7802_CTRL2_CRS(st->sample_rate));
-
-   if (ret < 0) {
-   mutex_unlock(>lock);
-   return ret;
-   }
+   if (ret < 0)
+   goto unlock;
}
 
if (st->client->irq)
ret = nau7802_read_irq(indio_dev, chan, val);
else
ret = nau7802_read_poll(indio_dev, chan, val);
-
+unlock:
mutex_unlock(>lock);
return ret;
 
-- 
2.16.2

[PATCH] iio/adc/nau7802: Improve unlocking of a mutex in nau7802_read_raw()

[SF Markus Elfring]

From: Markus Elfring 
Date: Tue, 13 Mar 2018 20:52:26 +0100

* Add a jump target so that a call of the function "mutex_unlock" is stored
  only once in this function implementation.

* Replace two calls by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
---
 drivers/iio/adc/nau7802.c | 15 +--
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/nau7802.c b/drivers/iio/adc/nau7802.c
index 8997e74a8847..68d06a492760 100644
--- a/drivers/iio/adc/nau7802.c
+++ b/drivers/iio/adc/nau7802.c
@@ -303,10 +303,8 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
 *   - Channel 2 is value 1 in the CHS register
 */
ret = i2c_smbus_read_byte_data(st->client, NAU7802_REG_CTRL2);
-   if (ret < 0) {
-   mutex_unlock(>lock);
-   return ret;
-   }
+   if (ret < 0)
+   goto unlock;
 
if (((ret & NAU7802_CTRL2_CHS_BIT) && !chan->channel) ||
(!(ret & NAU7802_CTRL2_CHS_BIT) &&
@@ -316,18 +314,15 @@ static int nau7802_read_raw(struct iio_dev *indio_dev,
NAU7802_REG_CTRL2,
NAU7802_CTRL2_CHS(chan->channel) |
NAU7802_CTRL2_CRS(st->sample_rate));
-
-   if (ret < 0) {
-   mutex_unlock(>lock);
-   return ret;
-   }
+   if (ret < 0)
+   goto unlock;
}
 
if (st->client->irq)
ret = nau7802_read_irq(indio_dev, chan, val);
else
ret = nau7802_read_poll(indio_dev, chan, val);
-
+unlock:
mutex_unlock(>lock);
return ret;
 
-- 
2.16.2