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authorJohan Hovold <johan@kernel.org>2015-05-04 17:10:30 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-05-12 10:46:40 +0200
commit3ff74be5c1a72df6d304dcb453f68e3c3bea3bdd (patch)
tree301c70d5cea8d288630022114d213724b953dad6 /drivers/gpio/gpiolib-sysfs.c
parentcecf58ab551f746c1e2b549d90b51a94b442d1e0 (diff)
downloadlinux-3ff74be5c1a72df6d304dcb453f68e3c3bea3bdd.tar.bz2
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>
Diffstat (limited to 'drivers/gpio/gpiolib-sysfs.c')
-rw-r--r--drivers/gpio/gpiolib-sysfs.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 658ed28e6d7d..d19bf234e878 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -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);