mirror of https://gitee.com/openkylin/linux.git
gpio: sysfs: add gpiod class-device data
Add gpiod class-device data. This is a first step in getting rid of the insane gpio-descriptor flag overloading, backward irq-interface implementation, and course grained sysfs-interface locking (a single static mutex for every operation on all exported gpios in a system). Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Johan Hovold
Linus Walleij
parent
f0b7866a02
commit
c43960fbcc
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@ -6,9 +6,14 @@
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#include <linux/gpio/driver.h>
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#include <linux/interrupt.h>
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#include <linux/kdev_t.h>
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#include <linux/slab.h>
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#include "gpiolib.h"
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struct gpiod_data {
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struct gpio_desc *desc;
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};
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static DEFINE_IDR(dirent_idr);
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@ -41,7 +46,8 @@ static DEFINE_MUTEX(sysfs_lock);
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static ssize_t direction_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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mutex_lock(&sysfs_lock);
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@ -58,7 +64,8 @@ static ssize_t direction_show(struct device *dev,
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static ssize_t direction_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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mutex_lock(&sysfs_lock);
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@ -80,7 +87,8 @@ static DEVICE_ATTR_RW(direction);
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static ssize_t value_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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mutex_lock(&sysfs_lock);
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@ -94,7 +102,8 @@ static ssize_t value_show(struct device *dev,
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static ssize_t value_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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mutex_lock(&sysfs_lock);
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@ -225,7 +234,8 @@ static const struct {
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static ssize_t edge_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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const struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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unsigned long mask;
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ssize_t status = 0;
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int i;
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@ -247,7 +257,8 @@ static ssize_t edge_show(struct device *dev,
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static ssize_t edge_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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int i;
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@ -297,7 +308,8 @@ static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
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static ssize_t active_low_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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const struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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mutex_lock(&sysfs_lock);
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@ -313,7 +325,8 @@ static ssize_t active_low_show(struct device *dev,
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static ssize_t active_low_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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ssize_t status;
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long value;
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@ -333,7 +346,8 @@ static umode_t gpio_is_visible(struct kobject *kobj, struct attribute *attr,
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int n)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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struct gpio_desc *desc = dev_get_drvdata(dev);
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struct gpiod_data *data = dev_get_drvdata(dev);
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struct gpio_desc *desc = data->desc;
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umode_t mode = attr->mode;
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bool show_direction = test_bit(FLAG_SYSFS_DIR, &desc->flags);
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@ -525,6 +539,7 @@ static struct class gpio_class = {
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int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
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{
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struct gpio_chip *chip;
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struct gpiod_data *data;
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unsigned long flags;
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int status;
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const char *ioname = NULL;
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@ -549,7 +564,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
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/* check if chip is being removed */
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if (!chip || !chip->cdev) {
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status = -ENODEV;
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goto fail_unlock;
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goto err_unlock;
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}
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spin_lock_irqsave(&gpio_lock, flags);
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@ -561,7 +576,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
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test_bit(FLAG_REQUESTED, &desc->flags),
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test_bit(FLAG_EXPORT, &desc->flags));
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status = -EPERM;
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goto fail_unlock;
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goto err_unlock;
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}
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if (chip->direction_input && chip->direction_output &&
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@ -571,33 +586,45 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
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spin_unlock_irqrestore(&gpio_lock, flags);
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data) {
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status = -ENOMEM;
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goto err_unlock;
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}
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data->desc = desc;
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offset = gpio_chip_hwgpio(desc);
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if (chip->names && chip->names[offset])
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ioname = chip->names[offset];
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dev = device_create_with_groups(&gpio_class, chip->dev,
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MKDEV(0, 0), desc, gpio_groups,
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MKDEV(0, 0), data, gpio_groups,
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ioname ? ioname : "gpio%u",
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desc_to_gpio(desc));
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if (IS_ERR(dev)) {
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status = PTR_ERR(dev);
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goto fail_unlock;
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goto err_free_data;
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}
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set_bit(FLAG_EXPORT, &desc->flags);
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mutex_unlock(&sysfs_lock);
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return 0;
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fail_unlock:
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err_free_data:
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kfree(data);
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err_unlock:
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mutex_unlock(&sysfs_lock);
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gpiod_dbg(desc, "%s: status %d\n", __func__, status);
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return status;
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}
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EXPORT_SYMBOL_GPL(gpiod_export);
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static int match_export(struct device *dev, const void *data)
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static int match_export(struct device *dev, const void *desc)
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{
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return dev_get_drvdata(dev) == data;
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struct gpiod_data *data = dev_get_drvdata(dev);
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return data->desc == desc;
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}
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/**
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@ -653,6 +680,7 @@ EXPORT_SYMBOL_GPL(gpiod_export_link);
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*/
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void gpiod_unexport(struct gpio_desc *desc)
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{
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struct gpiod_data *data;
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int status = 0;
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struct device *dev = NULL;
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@ -676,6 +704,7 @@ void gpiod_unexport(struct gpio_desc *desc)
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mutex_unlock(&sysfs_lock);
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if (dev) {
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data = dev_get_drvdata(dev);
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device_unregister(dev);
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/*
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* Release irq after deregistration to prevent race with
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@ -683,6 +712,7 @@ void gpiod_unexport(struct gpio_desc *desc)
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*/
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gpio_setup_irq(desc, dev, 0);
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put_device(dev);
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kfree(data);
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}
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if (status)
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