[PATCH] iio: temperature: tsys02d: Use guard(mutex) in tsys02d_write_raw()

[PATCH] iio: temperature: tsys02d: Use guard(mutex) in tsys02d_write_raw()

[lauraarakaki]

Replace the manual mutex_lock()/mutex_unlock() pair in
tsys02d_write_raw() with guard(mutex)() from the scope-based
cleanup helpers (include/linux/cleanup.h).

The previous code stored the return value of
ms_sensors_write_resolution() in a local variable solely to
bridge the gap between the manual mutex_unlock() call and the
return statement. Using guard(mutex)() removes the need for
both the intermediate variable and the explicit unlock call,
since the mutex is released automatically when the function
goes out of scope.

No functional change intended.

Signed-off-by: lauraarakaki <lauraarakaki23@gmail.com>
---
 drivers/iio/temperature/tsys02d.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/temperature/tsys02d.c b/drivers/iio/temperature/tsys02d.c
index 0cad27205667..55a55f2f4663 100644
--- a/drivers/iio/temperature/tsys02d.c
+++ b/drivers/iio/temperature/tsys02d.c
@@ -10,6 +10,7 @@
  *  http://www.meas-spec.com/downloads/Digital_Sensor_TSYS02D.pdf
  */
 
+#include <linux/cleanup.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
@@ -62,7 +63,7 @@ static int tsys02d_write_raw(struct iio_dev *indio_dev,
 			     int val, int val2, long mask)
 {
 	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
-	int i, ret;
+	int i;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
@@ -72,17 +73,13 @@ static int tsys02d_write_raw(struct iio_dev *indio_dev,
 				break;
 		if (i < 0)
 			return -EINVAL;
-		mutex_lock(&dev_data->lock);
+		guard(mutex)(&dev_data->lock);
 		dev_data->res_index = i;
-		ret = ms_sensors_write_resolution(dev_data, i);
-		mutex_unlock(&dev_data->lock);
-
-		return ret;
+		return ms_sensors_write_resolution(dev_data, i);
 	default:
 		return -EINVAL;
 	}
 }
-
 static const struct iio_chan_spec tsys02d_channels[] = {
 	{
 		.type = IIO_TEMP,
-- 
2.47.3

Re: [PATCH] iio: temperature: tsys02d: Use guard(mutex) in tsys02d_write_raw()

[Jonathan Cameron]

On Tue, 21 Apr 2026 12:40:01 -0300
lauraarakaki <lauraarakaki23@gmail.com> wrote:

> Replace the manual mutex_lock()/mutex_unlock() pair in
> tsys02d_write_raw() with guard(mutex)() from the scope-based
> cleanup helpers (include/linux/cleanup.h).
> 
Hi and welcome to IIO.

The wrap of this message is rather short. Normally we go
for 75 characters for a commit description.

> The previous code stored the return value of
> ms_sensors_write_resolution() in a local variable solely to
> bridge the gap between the manual mutex_unlock() call and the
> return statement. Using guard(mutex)() removes the need for
> both the intermediate variable and the explicit unlock call,
> since the mutex is released automatically when the function
> goes out of scope.
This paragraph is unnecessary detail.
> 
> No functional change intended.
> 
> Signed-off-by: lauraarakaki <lauraarakaki23@gmail.com>

> ---
>  drivers/iio/temperature/tsys02d.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iio/temperature/tsys02d.c b/drivers/iio/temperature/tsys02d.c
> index 0cad27205667..55a55f2f4663 100644
> --- a/drivers/iio/temperature/tsys02d.c
> +++ b/drivers/iio/temperature/tsys02d.c
> @@ -10,6 +10,7 @@
>   *  http://www.meas-spec.com/downloads/Digital_Sensor_TSYS02D.pdf
>   */
>  
> +#include <linux/cleanup.h>
>  #include <linux/init.h>
>  #include <linux/device.h>
>  #include <linux/kernel.h>
> @@ -62,7 +63,7 @@ static int tsys02d_write_raw(struct iio_dev *indio_dev,
>  			     int val, int val2, long mask)
>  {
>  	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
> -	int i, ret;
> +	int i;
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SAMP_FREQ:
> @@ -72,17 +73,13 @@ static int tsys02d_write_raw(struct iio_dev *indio_dev,
>  				break;
>  		if (i < 0)
>  			return -EINVAL;
> -		mutex_lock(&dev_data->lock);
> +		guard(mutex)(&dev_data->lock);
Unfortunately this broken because the non obvious definition of scope
in switch case statements.  You need to add {} in appropriate places.

See some similar threads from last few days.

>  		dev_data->res_index = i;
> -		ret = ms_sensors_write_resolution(dev_data, i);
> -		mutex_unlock(&dev_data->lock);
> -
> -		return ret;
> +		return ms_sensors_write_resolution(dev_data, i);
>  	default:
>  		return -EINVAL;
>  	}
>  }
> -
Unrelated change.  Always check for these and clean them up before posting.
>  static const struct iio_chan_spec tsys02d_channels[] = {
>  	{
>  		.type = IIO_TEMP,

Re: [PATCH] iio: temperature: tsys02d: Use guard(mutex) in tsys02d_write_raw()

[Andy Shevchenko]

On Tue, Apr 21, 2026 at 06:47:09PM -0300, Laura Arakaki wrote:
> Hi,
> 
> Thanks for the review.
> 
> I'll address the issues:
> 
> - Fix scope in switch case by adding proper braces for guard(mutex)
> - Simplify the commit message
> - Remove unrelated changes
> 
> I'll send a v2 shortly.

No, please slow down. Take your time to review patches from others in this area
(IIO subsystem), read documentation, et cetera.

There are too many patches now that overload the capacity of the human reviewers.
Also by reviewing others' patches you will learn a lot without even submitting
anything.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] iio: temperature: tsys02d: Use guard(mutex) in tsys02d_write_raw()

[Andy Shevchenko]

On Tue, Apr 21, 2026 at 12:40:01PM -0300, lauraarakaki wrote:
> Replace the manual mutex_lock()/mutex_unlock() pair in
> tsys02d_write_raw() with guard(mutex)() from the scope-based
> cleanup helpers (include/linux/cleanup.h).
> 
> The previous code stored the return value of
> ms_sensors_write_resolution() in a local variable solely to
> bridge the gap between the manual mutex_unlock() call and the
> return statement. Using guard(mutex)() removes the need for
> both the intermediate variable and the explicit unlock call,
> since the mutex is released automatically when the function
> goes out of scope.
> 
> No functional change intended.

> Signed-off-by: lauraarakaki <lauraarakaki23@gmail.com>

Read documentation, you need to use real name (as in documents).

> ---
>  
> +#include <linux/cleanup.h>
>  #include <linux/init.h>
>  #include <linux/device.h>
>  #include <linux/kernel.h>

Preferable to get a prerequisite that sorts headers alphabetically and
(optionally) another patch to move to follow IWYU principle.

...

Now the most important point of this review. All of the above you may
get by helping in reviewing the patches in Linux IIO mailing list
(lore.kernel.org/linux-iio).

TL;DR: I will be glad to see a newcomer to participate in the reviewing
first.

-- 
With Best Regards,
Andy Shevchenko