[PATCH v2] iio: imu: kmx61: Use guard(mutex)() family over manual locking

[PATCH v2] iio: imu: kmx61: Use guard(mutex)() family over manual locking

[Maxwell Doose]

Include linux/cleanup.h to take advantage of new macros.

Replace manual mutex_lock() and mutex_unlock() calls across the file
with guard(mutex)() and scoped_guard() where appropriate. This will help
modernize the driver with up-to-date functions/macros.

Remove now redundant gotos and ret variables, as the new RAII macros
make them unneeded.

Signed-off-by: Maxwell Doose <m32285159@gmail.com>
---
 v2:
 - Remove redundant blank line per Andy.
 - Put kmx61_set_mode() function call in kmx61_runtime_suspend() on one
   line per Andy.

 drivers/iio/imu/kmx61.c | 76 ++++++++++++++---------------------------
 1 file changed, 25 insertions(+), 51 deletions(-)

diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
index 3cd91d8a89ee..6d2e98607d35 100644
--- a/drivers/iio/imu/kmx61.c
+++ b/drivers/iio/imu/kmx61.c
@@ -7,6 +7,7 @@
  * IIO driver for KMX61 (7-bit I2C slave address 0x0E or 0x0F).
  */
 
+#include <linux/cleanup.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/mod_devicetable.h>
@@ -794,25 +795,20 @@ static int kmx61_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
-		mutex_lock(&data->lock);
+		guard(mutex)(&data->lock);
 
 		ret = kmx61_set_power_state(data, true, chan->address);
-		if (ret) {
-			mutex_unlock(&data->lock);
+		if (ret)
 			return ret;
-		}
 
 		ret = kmx61_read_measurement(data, base_reg, chan->scan_index);
 		if (ret < 0) {
 			kmx61_set_power_state(data, false, chan->address);
-			mutex_unlock(&data->lock);
 			return ret;
 		}
 		*val = sign_extend32(ret >> chan->scan_type.shift,
 				     chan->scan_type.realbits - 1);
 		ret = kmx61_set_power_state(data, false, chan->address);
-
-		mutex_unlock(&data->lock);
 		if (ret)
 			return ret;
 		return IIO_VAL_INT;
@@ -834,9 +830,8 @@ static int kmx61_read_raw(struct iio_dev *indio_dev,
 		if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)
 			return -EINVAL;
 
-		mutex_lock(&data->lock);
-		ret = kmx61_get_odr(data, val, val2, chan->address);
-		mutex_unlock(&data->lock);
+		scoped_guard(mutex, &data->lock)
+			ret = kmx61_get_odr(data, val, val2, chan->address);
 		if (ret)
 			return -EINVAL;
 		return IIO_VAL_INT_PLUS_MICRO;
@@ -856,19 +851,15 @@ static int kmx61_write_raw(struct iio_dev *indio_dev,
 		if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)
 			return -EINVAL;
 
-		mutex_lock(&data->lock);
-		ret = kmx61_set_odr(data, val, val2, chan->address);
-		mutex_unlock(&data->lock);
-		return ret;
+		guard(mutex)(&data->lock);
+		return kmx61_set_odr(data, val, val2, chan->address);
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_ACCEL:
 			if (val != 0)
 				return -EINVAL;
-			mutex_lock(&data->lock);
-			ret = kmx61_set_scale(data, val2);
-			mutex_unlock(&data->lock);
-			return ret;
+			guard(mutex)(&data->lock);
+			return kmx61_set_scale(data, val2);
 		default:
 			return -EINVAL;
 		}
@@ -945,28 +936,25 @@ static int kmx61_write_event_config(struct iio_dev *indio_dev,
 	if (state && data->ev_enable_state)
 		return 0;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	if (!state && data->motion_trig_on) {
 		data->ev_enable_state = false;
-		goto err_unlock;
+		return ret;
 	}
 
 	ret = kmx61_set_power_state(data, state, KMX61_ACC);
 	if (ret < 0)
-		goto err_unlock;
+		return ret;
 
 	ret = kmx61_setup_any_motion_interrupt(data, state);
 	if (ret < 0) {
 		kmx61_set_power_state(data, false, KMX61_ACC);
-		goto err_unlock;
+		return ret;
 	}
 
 	data->ev_enable_state = state;
 
-err_unlock:
-	mutex_unlock(&data->lock);
-
 	return ret;
 }
 
@@ -1020,11 +1008,11 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 	struct kmx61_data *data = kmx61_get_data(indio_dev);
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	if (!state && data->ev_enable_state && data->motion_trig_on) {
 		data->motion_trig_on = false;
-		goto err_unlock;
+		return ret;
 	}
 
 	if (data->acc_dready_trig == trig || data->motion_trig == trig)
@@ -1034,7 +1022,7 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 
 	ret = kmx61_set_power_state(data, state, device);
 	if (ret < 0)
-		goto err_unlock;
+		return ret;
 
 	if (data->acc_dready_trig == trig || data->mag_dready_trig == trig)
 		ret = kmx61_setup_new_data_interrupt(data, state, device);
@@ -1042,7 +1030,7 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		ret = kmx61_setup_any_motion_interrupt(data, state);
 	if (ret < 0) {
 		kmx61_set_power_state(data, false, device);
-		goto err_unlock;
+		return ret;
 	}
 
 	if (data->acc_dready_trig == trig)
@@ -1051,8 +1039,6 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		data->mag_dready_trig_on = state;
 	else
 		data->motion_trig_on = state;
-err_unlock:
-	mutex_unlock(&data->lock);
 
 	return ret;
 }
@@ -1195,19 +1181,17 @@ static irqreturn_t kmx61_trigger_handler(int irq, void *p)
 	else
 		base = KMX61_MAG_XOUT_L;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	iio_for_each_active_channel(indio_dev, bit) {
 		ret = kmx61_read_measurement(data, base, bit);
 		if (ret < 0) {
-			mutex_unlock(&data->lock);
-			goto err;
+			iio_trigger_notify_done(indio_dev->trig);
+			return IRQ_HANDLED;
 		}
 		buffer[i++] = ret;
 	}
-	mutex_unlock(&data->lock);
 
 	iio_push_to_buffers(indio_dev, buffer);
-err:
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;
@@ -1419,22 +1403,16 @@ static void kmx61_remove(struct i2c_client *client)
 		iio_trigger_unregister(data->motion_trig);
 	}
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
-	mutex_unlock(&data->lock);
 }
 
 static int kmx61_suspend(struct device *dev)
 {
-	int ret;
 	struct kmx61_data *data = i2c_get_clientdata(to_i2c_client(dev));
 
-	mutex_lock(&data->lock);
-	ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG,
-			     false);
-	mutex_unlock(&data->lock);
-
-	return ret;
+	guard(mutex)(&data->lock);
+	return kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, false);
 }
 
 static int kmx61_resume(struct device *dev)
@@ -1453,13 +1431,9 @@ static int kmx61_resume(struct device *dev)
 static int kmx61_runtime_suspend(struct device *dev)
 {
 	struct kmx61_data *data = i2c_get_clientdata(to_i2c_client(dev));
-	int ret;
 
-	mutex_lock(&data->lock);
-	ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
-	mutex_unlock(&data->lock);
-
-	return ret;
+	guard(mutex)(&data->lock);
+	return kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
 }
 
 static int kmx61_runtime_resume(struct device *dev)

base-commit: 7fd2df204f342fc17d1a0bfcd474b24232fb0f32
-- 
2.54.0

Re: [PATCH v2] iio: imu: kmx61: Use guard(mutex)() family over manual locking

[Maxwell Doose]

Hi,

On Mon, May 4, 2026 at 7:55 PM Maxwell Doose <m32285159@gmail.com> wrote:
>
> Include linux/cleanup.h to take advantage of new macros.
>
> Replace manual mutex_lock() and mutex_unlock() calls across the file
> with guard(mutex)() and scoped_guard() where appropriate. This will help
> modernize the driver with up-to-date functions/macros.
>
> Remove now redundant gotos and ret variables, as the new RAII macros
> make them unneeded.
>
> Signed-off-by: Maxwell Doose <m32285159@gmail.com>
> ---
>  v2:
>  - Remove redundant blank line per Andy.
>  - Put kmx61_set_mode() function call in kmx61_runtime_suspend() on one
>    line per Andy.
>
>  drivers/iio/imu/kmx61.c | 76 ++++++++++++++---------------------------
>  1 file changed, 25 insertions(+), 51 deletions(-)
[snip]

I just got the report in from the CI bot on the v1, and there are
still things in this patch that need to be fixed, consider this
superseded. I'm going to be writing a v3 in the morning (my time) to
resolve this.

best regards,
max

Re: [PATCH v2] iio: imu: kmx61: Use guard(mutex)() family over manual locking

[Andy Shevchenko]

On Mon, May 04, 2026 at 11:46:04PM -0500, Maxwell Doose wrote:
> On Mon, May 4, 2026 at 7:55 PM Maxwell Doose <m32285159@gmail.com> wrote:
> >
> > Include linux/cleanup.h to take advantage of new macros.
> >
> > Replace manual mutex_lock() and mutex_unlock() calls across the file
> > with guard(mutex)() and scoped_guard() where appropriate. This will help
> > modernize the driver with up-to-date functions/macros.
> >
> > Remove now redundant gotos and ret variables, as the new RAII macros
> > make them unneeded.

[snip]

> I just got the report in from the CI bot on the v1, and there are
> still things in this patch that need to be fixed, consider this
> superseded. I'm going to be writing a v3 in the morning (my time) to
> resolve this.

Yes, you need to have a dedicated scope for guard()(). So, each case
in the switch that uses guard has to define the scope, id est be like

	case FOO: {
		...
		break; // or return ...;
	}

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] iio: imu: kmx61: Use guard(mutex)() family over manual locking

[Markus Elfring]

…
> Replace manual mutex_lock() and mutex_unlock() calls across the file
…

I find the word “family” inappropriate in the summary phrase.

Regards,
Markus