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gpio: sysfs: reduce gpiochip-export locking scope 

Reduce scope of sysfs_lock protection during chip export and unexport,
which is only needed to prevent gpiod (re-)exports during chip removal.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
hifive-unleashed-5.1
Johan Hovold 2015-05-04 17:10:30 +02:00 committed by Linus Walleij
parent cecf58ab55
commit 3ff74be5c1
1 changed files with 4 additions and 3 deletions
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7
drivers/gpio/gpiolib-sysfs.c
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@ -779,7 +779,6 @@ int gpiochip_export(struct gpio_chip *chip)
return 0;
/* use chip->base for the ID; it's already known to be unique */
mutex_lock(&sysfs_lock);
dev = device_create_with_groups(&gpio_class, chip->dev, MKDEV(0, 0),
chip, gpiochip_groups,
"gpiochip%d", chip->base);
@ -787,6 +786,8 @@ int gpiochip_export(struct gpio_chip *chip)
status = PTR_ERR(dev);
else
status = 0;
mutex_lock(&sysfs_lock);
chip->exported = (status == 0);
mutex_unlock(&sysfs_lock);
@ -803,17 +804,17 @@ void gpiochip_unexport(struct gpio_chip *chip)
struct gpio_desc *desc;
unsigned int i;
mutex_lock(&sysfs_lock);
dev = class_find_device(&gpio_class, NULL, chip, match_export);
if (dev) {
put_device(dev);
device_unregister(dev);
/* prevent further gpiod exports */
mutex_lock(&sysfs_lock);
chip->exported = false;
mutex_unlock(&sysfs_lock);
status = 0;
} else
status = -ENODEV;
mutex_unlock(&sysfs_lock);
if (status)
chip_dbg(chip, "%s: status %d\n", __func__, status);