gpio: sysfs: remove redundant export tests

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@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index e4b079e..10baf31 100644 (file)
--- 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);