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* [PATCH v1 1/1] gpiolib: Use sysfs_emit() in "show" functions
@ 2021-05-18 12:09 Andy Shevchenko
  2021-05-21 12:55 ` Bartosz Golaszewski
  0 siblings, 1 reply; 2+ messages in thread
From: Andy Shevchenko @ 2021-05-18 12:09 UTC (permalink / raw)
  To: Andy Shevchenko, linux-gpio, linux-kernel
  Cc: Linus Walleij, Bartosz Golaszewski

The sysfs_emit() function was introduced to make it less ambiguous
which function is preferred when writing to the output buffer in
a "show" callback [1].

Convert the GPIO library sysfs interface from sprintf() to sysfs_emit()
accordingly, as the latter is aware of the PAGE_SIZE buffer and correctly
returns the number of bytes written into the buffer.

No functional change intended.

[1] Documentation/filesystems/sysfs.rst

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/gpio/gpiolib-sysfs.c | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 7c5afd999210..d836aba91d3c 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -66,9 +66,7 @@ static ssize_t direction_show(struct device *dev,
 	mutex_lock(&data->mutex);
 
 	gpiod_get_direction(desc);
-	status = sprintf(buf, "%s\n",
-			test_bit(FLAG_IS_OUT, &desc->flags)
-				? "out" : "in");
+	status = sysfs_emit(buf, "%s\n", test_bit(FLAG_IS_OUT, &desc->flags) ? "out" : "in");
 
 	mutex_unlock(&data->mutex);
 
@@ -109,13 +107,9 @@ static ssize_t value_show(struct device *dev,
 	mutex_lock(&data->mutex);
 
 	status = gpiod_get_value_cansleep(desc);
-	if (status < 0)
-		goto err;
+	if (status >= 0)
+		status = sysfs_emit(buf, "%zd\n", status);
 
-	buf[0] = '0' + status;
-	buf[1] = '\n';
-	status = 2;
-err:
 	mutex_unlock(&data->mutex);
 
 	return status;
@@ -249,11 +243,11 @@ static ssize_t edge_show(struct device *dev,
 	mutex_lock(&data->mutex);
 
 	for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
-		if (data->irq_flags == trigger_types[i].flags) {
-			status = sprintf(buf, "%s\n", trigger_types[i].name);
+		if (data->irq_flags == trigger_types[i].flags)
 			break;
-		}
 	}
+	if (i < ARRAY_SIZE(trigger_types))
+		status = sysfs_emit(buf, "%s\n", trigger_types[i].name);
 
 	mutex_unlock(&data->mutex);
 
@@ -333,8 +327,7 @@ static ssize_t active_low_show(struct device *dev,
 
 	mutex_lock(&data->mutex);
 
-	status = sprintf(buf, "%d\n",
-				!!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
+	status = sysfs_emit(buf, "%d\n", !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
 
 	mutex_unlock(&data->mutex);
 
@@ -412,7 +405,7 @@ static ssize_t base_show(struct device *dev,
 {
 	const struct gpio_chip	*chip = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%d\n", chip->base);
+	return sysfs_emit(buf, "%d\n", chip->base);
 }
 static DEVICE_ATTR_RO(base);
 
@@ -421,7 +414,7 @@ static ssize_t label_show(struct device *dev,
 {
 	const struct gpio_chip	*chip = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%s\n", chip->label ? : "");
+	return sysfs_emit(buf, "%s\n", chip->label ?: "");
 }
 static DEVICE_ATTR_RO(label);
 
@@ -430,7 +423,7 @@ static ssize_t ngpio_show(struct device *dev,
 {
 	const struct gpio_chip	*chip = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%u\n", chip->ngpio);
+	return sysfs_emit(buf, "%u\n", chip->ngpio);
 }
 static DEVICE_ATTR_RO(ngpio);
 
-- 
2.30.2


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH v1 1/1] gpiolib: Use sysfs_emit() in "show" functions
  2021-05-18 12:09 [PATCH v1 1/1] gpiolib: Use sysfs_emit() in "show" functions Andy Shevchenko
@ 2021-05-21 12:55 ` Bartosz Golaszewski
  0 siblings, 0 replies; 2+ messages in thread
From: Bartosz Golaszewski @ 2021-05-21 12:55 UTC (permalink / raw)
  To: Andy Shevchenko; +Cc: linux-gpio, LKML, Linus Walleij

On Tue, May 18, 2021 at 2:09 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> The sysfs_emit() function was introduced to make it less ambiguous
> which function is preferred when writing to the output buffer in
> a "show" callback [1].
>
> Convert the GPIO library sysfs interface from sprintf() to sysfs_emit()
> accordingly, as the latter is aware of the PAGE_SIZE buffer and correctly
> returns the number of bytes written into the buffer.
>
> No functional change intended.
>
> [1] Documentation/filesystems/sysfs.rst
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/gpio/gpiolib-sysfs.c | 27 ++++++++++-----------------
>  1 file changed, 10 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
> index 7c5afd999210..d836aba91d3c 100644
> --- a/drivers/gpio/gpiolib-sysfs.c
> +++ b/drivers/gpio/gpiolib-sysfs.c
> @@ -66,9 +66,7 @@ static ssize_t direction_show(struct device *dev,
>         mutex_lock(&data->mutex);
>
>         gpiod_get_direction(desc);
> -       status = sprintf(buf, "%s\n",
> -                       test_bit(FLAG_IS_OUT, &desc->flags)
> -                               ? "out" : "in");
> +       status = sysfs_emit(buf, "%s\n", test_bit(FLAG_IS_OUT, &desc->flags) ? "out" : "in");
>
>         mutex_unlock(&data->mutex);
>
> @@ -109,13 +107,9 @@ static ssize_t value_show(struct device *dev,
>         mutex_lock(&data->mutex);
>
>         status = gpiod_get_value_cansleep(desc);
> -       if (status < 0)
> -               goto err;
> +       if (status >= 0)
> +               status = sysfs_emit(buf, "%zd\n", status);
>
> -       buf[0] = '0' + status;
> -       buf[1] = '\n';
> -       status = 2;
> -err:
>         mutex_unlock(&data->mutex);
>
>         return status;
> @@ -249,11 +243,11 @@ static ssize_t edge_show(struct device *dev,
>         mutex_lock(&data->mutex);
>
>         for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
> -               if (data->irq_flags == trigger_types[i].flags) {
> -                       status = sprintf(buf, "%s\n", trigger_types[i].name);
> +               if (data->irq_flags == trigger_types[i].flags)
>                         break;
> -               }
>         }
> +       if (i < ARRAY_SIZE(trigger_types))
> +               status = sysfs_emit(buf, "%s\n", trigger_types[i].name);
>
>         mutex_unlock(&data->mutex);
>
> @@ -333,8 +327,7 @@ static ssize_t active_low_show(struct device *dev,
>
>         mutex_lock(&data->mutex);
>
> -       status = sprintf(buf, "%d\n",
> -                               !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
> +       status = sysfs_emit(buf, "%d\n", !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
>
>         mutex_unlock(&data->mutex);
>
> @@ -412,7 +405,7 @@ static ssize_t base_show(struct device *dev,
>  {
>         const struct gpio_chip  *chip = dev_get_drvdata(dev);
>
> -       return sprintf(buf, "%d\n", chip->base);
> +       return sysfs_emit(buf, "%d\n", chip->base);
>  }
>  static DEVICE_ATTR_RO(base);
>
> @@ -421,7 +414,7 @@ static ssize_t label_show(struct device *dev,
>  {
>         const struct gpio_chip  *chip = dev_get_drvdata(dev);
>
> -       return sprintf(buf, "%s\n", chip->label ? : "");
> +       return sysfs_emit(buf, "%s\n", chip->label ?: "");
>  }
>  static DEVICE_ATTR_RO(label);
>
> @@ -430,7 +423,7 @@ static ssize_t ngpio_show(struct device *dev,
>  {
>         const struct gpio_chip  *chip = dev_get_drvdata(dev);
>
> -       return sprintf(buf, "%u\n", chip->ngpio);
> +       return sysfs_emit(buf, "%u\n", chip->ngpio);
>  }
>  static DEVICE_ATTR_RO(ngpio);
>
> --
> 2.30.2
>

Applied, thanks!

Bartosz

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-05-21 12:56 UTC | newest]

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2021-05-21 12:55 ` Bartosz Golaszewski

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