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authorJohan Hovold <johan@kernel.org>2015-05-04 17:10:43 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-05-12 10:47:35 +0200
commit56d30ec14c13303eb9e7c34358ba6549fc7b0121 (patch)
tree1d39883f05c4a462e55a645c442db81241debb55 /drivers/gpio
parente4339ce32372e2f8c98222c0923b79476c29a309 (diff)
gpio: sysfs: clean up gpiod_export_link locking
Drop unnecessary locking from gpiod_export_link. If the class device has not already been unregistered, class_find_device returns the ref-counted class device so there's no need for locking. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib-sysfs.c28
1 files changed, 8 insertions, 20 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 1161a46618dd..682e4d34999c 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -631,34 +631,22 @@ static int match_export(struct device *dev, const void *desc)
int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc)
{
- int status = -EINVAL;
+ struct device *cdev;
+ int ret;
if (!desc) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
- mutex_lock(&sysfs_lock);
-
- if (test_bit(FLAG_EXPORT, &desc->flags)) {
- struct device *tdev;
-
- tdev = class_find_device(&gpio_class, NULL, desc, match_export);
- if (tdev != NULL) {
- status = sysfs_create_link(&dev->kobj, &tdev->kobj,
- name);
- put_device(tdev);
- } else {
- status = -ENODEV;
- }
- }
-
- mutex_unlock(&sysfs_lock);
+ cdev = class_find_device(&gpio_class, NULL, desc, match_export);
+ if (!cdev)
+ return -ENODEV;
- if (status)
- gpiod_dbg(desc, "%s: status %d\n", __func__, status);
+ ret = sysfs_create_link(&dev->kobj, &cdev->kobj, name);
+ put_device(cdev);
- return status;
+ return ret;
}
EXPORT_SYMBOL_GPL(gpiod_export_link);