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gpio: remove the RW semaphore from the GPIO device

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With all accesses to gdev->chip being protected with SRCU, we can now
remove the RW-semaphore specific to the character device which
fulfilled the same role up to this point.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This commit is contained in:
Bartosz Golaszewski
2024-01-24 17:02:03 +01:00
parent d83cee3d2b
commit f067372c6a
2 changed files with 0 additions and 9 deletions
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4
drivers/gpio/gpiolib.c
View File

@@ -963,7 +963,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
init_rwsem(&gdev->sem);
ret = init_srcu_struct(&gdev->srcu);
if (ret)
@@ -1102,8 +1101,6 @@ void gpiochip_remove(struct gpio_chip *gc)
struct gpio_device *gdev = gc->gpiodev;
unsigned int i;
down_write(&gdev->sem);
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
gpiochip_sysfs_unregister(gdev);
gpiochip_free_hogs(gc);
@@ -1142,7 +1139,6 @@ void gpiochip_remove(struct gpio_chip *gc)
* gone.
*/
gcdev_unregister(gdev);
up_write(&gdev->sem);
gpio_device_put(gdev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);

5
drivers/gpio/gpiolib.h
View File

@@ -16,7 +16,6 @@
#include <linux/gpio/driver.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/rwsem.h>
#include <linux/srcu.h>
#define GPIOCHIP_NAME "gpiochip"
@@ -46,9 +45,6 @@
* requested, released or reconfigured
* @device_notifier: used to notify character device wait queues about the GPIO
* device being unregistered
* @sem: protects the structure from a NULL-pointer dereference of @chip by
* user-space operations when the device gets unregistered during
* a hot-unplug event
* @srcu: protects the pointer to the underlying GPIO chip
* @pin_ranges: range of pins served by the GPIO driver
*
@@ -73,7 +69,6 @@ struct gpio_device {
struct list_head list;
struct blocking_notifier_head line_state_notifier;
struct blocking_notifier_head device_notifier;
struct rw_semaphore sem;
struct srcu_struct srcu;
#ifdef CONFIG_PINCTRL