[PATCH 1/5] gpio: sysfs: use cleanup guards for gpiod_data::mutex

From: Bartosz Golaszewski
Date: Thu Oct 24 2024 - 07:33:47 EST


From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Shrink the code and drop some goto labels by using lock guards around
gpiod_data::mutex.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
drivers/gpio/gpiolib-sysfs.c | 57 +++++++++++++-------------------------------
1 file changed, 17 insertions(+), 40 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 0c713baa7784..3ccb41a93ea7 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -77,12 +77,10 @@ static ssize_t direction_show(struct device *dev,
struct gpio_desc *desc = data->desc;
int value;

- mutex_lock(&data->mutex);
-
- gpiod_get_direction(desc);
- value = !!test_bit(FLAG_IS_OUT, &desc->flags);
-
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex) {
+ gpiod_get_direction(desc);
+ value = !!test_bit(FLAG_IS_OUT, &desc->flags);
+ }

return sysfs_emit(buf, "%s\n", value ? "out" : "in");
}
@@ -94,7 +92,7 @@ static ssize_t direction_store(struct device *dev,
struct gpio_desc *desc = data->desc;
ssize_t status;

- mutex_lock(&data->mutex);
+ guard(mutex)(&data->mutex);

if (sysfs_streq(buf, "high"))
status = gpiod_direction_output_raw(desc, 1);
@@ -105,8 +103,6 @@ static ssize_t direction_store(struct device *dev,
else
status = -EINVAL;

- mutex_unlock(&data->mutex);
-
return status ? : size;
}
static DEVICE_ATTR_RW(direction);
@@ -118,11 +114,8 @@ static ssize_t value_show(struct device *dev,
struct gpio_desc *desc = data->desc;
ssize_t status;

- mutex_lock(&data->mutex);
-
- status = gpiod_get_value_cansleep(desc);
-
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex)
+ status = gpiod_get_value_cansleep(desc);

if (status < 0)
return status;
@@ -140,7 +133,7 @@ static ssize_t value_store(struct device *dev,

status = kstrtol(buf, 0, &value);

- mutex_lock(&data->mutex);
+ guard(mutex)(&data->mutex);

if (!test_bit(FLAG_IS_OUT, &desc->flags)) {
status = -EPERM;
@@ -149,8 +142,6 @@ static ssize_t value_store(struct device *dev,
status = size;
}

- mutex_unlock(&data->mutex);
-
return status;
}
static DEVICE_ATTR_PREALLOC(value, S_IWUSR | S_IRUGO, value_show, value_store);
@@ -253,11 +244,8 @@ static ssize_t edge_show(struct device *dev,
struct gpiod_data *data = dev_get_drvdata(dev);
int flags;

- mutex_lock(&data->mutex);
-
- flags = data->irq_flags;
-
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex)
+ flags = data->irq_flags;

if (flags >= ARRAY_SIZE(trigger_names))
return 0;
@@ -276,12 +264,10 @@ static ssize_t edge_store(struct device *dev,
if (flags < 0)
return flags;

- mutex_lock(&data->mutex);
+ guard(mutex)(&data->mutex);

- if (flags == data->irq_flags) {
- status = size;
- goto out_unlock;
- }
+ if (flags == data->irq_flags)
+ return size;

if (data->irq_flags)
gpio_sysfs_free_irq(dev);
@@ -292,9 +278,6 @@ static ssize_t edge_store(struct device *dev,
status = size;
}

-out_unlock:
- mutex_unlock(&data->mutex);
-
return status;
}
static DEVICE_ATTR_RW(edge);
@@ -330,11 +313,8 @@ static ssize_t active_low_show(struct device *dev,
struct gpio_desc *desc = data->desc;
int value;

- mutex_lock(&data->mutex);
-
- value = !!test_bit(FLAG_ACTIVE_LOW, &desc->flags);
-
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex)
+ value = !!test_bit(FLAG_ACTIVE_LOW, &desc->flags);

return sysfs_emit(buf, "%d\n", value);
}
@@ -350,11 +330,8 @@ static ssize_t active_low_store(struct device *dev,
if (status)
return status;

- mutex_lock(&data->mutex);
-
- status = gpio_sysfs_set_active_low(dev, value);
-
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex)
+ status = gpio_sysfs_set_active_low(dev, value);

return status ? : size;
}

--
2.45.2