[PATCH v2 11/23] gpio: sysfs: remove redundant export tests

From: Johan Hovold
Date: Mon May 04 2015 - 11:18:52 EST


The attribute operations will never be called for an unregistered device
so remove redundant checks for FLAG_EXPORT.

Note that kernfs will also guarantee that any active sysfs operation has
finished before the attribute is removed during deregistration.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/gpio/gpiolib-sysfs.c | 74 ++++++++++++++------------------------------
1 file changed, 23 insertions(+), 51 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index e4b079eec9bc..10baf31efe74 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -46,14 +46,10 @@ static ssize_t direction_show(struct device *dev,

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags)) {
- status = -EIO;
- } else {
- gpiod_get_direction(desc);
- status = sprintf(buf, "%s\n",
+ gpiod_get_direction(desc);
+ status = sprintf(buf, "%s\n",
test_bit(FLAG_IS_OUT, &desc->flags)
? "out" : "in");
- }

mutex_unlock(&sysfs_lock);
return status;
@@ -67,9 +63,7 @@ static ssize_t direction_store(struct device *dev,

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else if (sysfs_streq(buf, "high"))
+ if (sysfs_streq(buf, "high"))
status = gpiod_direction_output_raw(desc, 1);
else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
status = gpiod_direction_output_raw(desc, 0);
@@ -91,10 +85,7 @@ static ssize_t value_show(struct device *dev,

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else
- status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
+ status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));

mutex_unlock(&sysfs_lock);
return status;
@@ -108,11 +99,9 @@ static ssize_t value_store(struct device *dev,

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else if (!test_bit(FLAG_IS_OUT, &desc->flags))
+ if (!test_bit(FLAG_IS_OUT, &desc->flags)) {
status = -EPERM;
- else {
+ } else {
long value;

status = kstrtol(buf, 0, &value);
@@ -237,23 +226,18 @@ static ssize_t edge_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
const struct gpio_desc *desc = dev_get_drvdata(dev);
- ssize_t status;
+ unsigned long mask;
+ ssize_t status = 0;
+ int i;

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else {
- int i;
-
- status = 0;
- for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
- if ((desc->flags & GPIO_TRIGGER_MASK)
- == trigger_types[i].flags) {
- status = sprintf(buf, "%s\n",
- trigger_types[i].name);
- break;
- }
+ for (i = 0; i < ARRAY_SIZE(trigger_types); i++) {
+ mask = desc->flags & GPIO_TRIGGER_MASK;
+ if (mask == trigger_types[i].flags) {
+ status = sprintf(buf, "%s\n", trigger_types[i].name);
+ break;
+ }
}

mutex_unlock(&sysfs_lock);
@@ -275,13 +259,9 @@ static ssize_t edge_store(struct device *dev,
found:
mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else {
- status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
- if (!status)
- status = size;
- }
+ status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
+ if (!status)
+ status = size;

mutex_unlock(&sysfs_lock);

@@ -322,10 +302,7 @@ static ssize_t active_low_show(struct device *dev,

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags))
- status = -EIO;
- else
- status = sprintf(buf, "%d\n",
+ status = sprintf(buf, "%d\n",
!!test_bit(FLAG_ACTIVE_LOW, &desc->flags));

mutex_unlock(&sysfs_lock);
@@ -338,18 +315,13 @@ static ssize_t active_low_store(struct device *dev,
{
struct gpio_desc *desc = dev_get_drvdata(dev);
ssize_t status;
+ long value;

mutex_lock(&sysfs_lock);

- if (!test_bit(FLAG_EXPORT, &desc->flags)) {
- status = -EIO;
- } else {
- long value;
-
- status = kstrtol(buf, 0, &value);
- if (status == 0)
- status = sysfs_set_active_low(desc, dev, value != 0);
- }
+ status = kstrtol(buf, 0, &value);
+ if (status == 0)
+ status = sysfs_set_active_low(desc, dev, value != 0);

mutex_unlock(&sysfs_lock);

--
2.0.5

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