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leds: Fix leds_list_lock locking issues 

Covert leds_list_lock to a rw_sempahore to match previous LED trigger
locking fixes, fixing lock ordering.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
hifive-unleashed-5.1
Richard Purdie 2007-12-31 23:09:44 +00:00
parent e697789d64
commit 72f8da329e
4 changed files with 12 additions and 11 deletions
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8
drivers/leds/led-class.c
View File

@ -106,9 +106,9 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
goto err_out;
/* add to the list of leds */
write_lock(&leds_list_lock);
down_write(&leds_list_lock);
list_add_tail(&led_cdev->node, &leds_list);
write_unlock(&leds_list_lock);
up_write(&leds_list_lock);
#ifdef CONFIG_LEDS_TRIGGERS
init_rwsem(&led_cdev->trigger_lock);
@ -155,9 +155,9 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
device_unregister(led_cdev->dev);
write_lock(&leds_list_lock);
down_write(&leds_list_lock);
list_del(&led_cdev->node);
write_unlock(&leds_list_lock);
up_write(&leds_list_lock);
}
EXPORT_SYMBOL_GPL(led_classdev_unregister);

4
drivers/leds/led-core.c
View File

@ -14,11 +14,11 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/leds.h>
#include "leds.h"
DEFINE_RWLOCK(leds_list_lock);
DECLARE_RWSEM(leds_list_lock);
LIST_HEAD(leds_list);
EXPORT_SYMBOL_GPL(leds_list);

8
drivers/leds/led-triggers.c
View File

@ -169,7 +169,7 @@ int led_trigger_register(struct led_trigger *trigger)
up_write(&triggers_list_lock);
/* Register with any LEDs that have this as a default trigger */
read_lock(&leds_list_lock);
down_read(&leds_list_lock);
list_for_each_entry(led_cdev, &leds_list, node) {
down_write(&led_cdev->trigger_lock);
if (!led_cdev->trigger && led_cdev->default_trigger &&
@ -177,7 +177,7 @@ int led_trigger_register(struct led_trigger *trigger)
led_trigger_set(led_cdev, trigger);
up_write(&led_cdev->trigger_lock);
}
read_unlock(&leds_list_lock);
up_read(&leds_list_lock);
return 0;
}
@ -212,14 +212,14 @@ void led_trigger_unregister(struct led_trigger *trigger)
up_write(&triggers_list_lock);
/* Remove anyone actively using this trigger */
read_lock(&leds_list_lock);
down_read(&leds_list_lock);
list_for_each_entry(led_cdev, &leds_list, node) {
down_write(&led_cdev->trigger_lock);
if (led_cdev->trigger == trigger)
led_trigger_set(led_cdev, NULL);
up_write(&led_cdev->trigger_lock);
}
read_unlock(&leds_list_lock);
up_read(&leds_list_lock);
}
void led_trigger_unregister_simple(struct led_trigger *trigger)

3
drivers/leds/leds.h
View File

@ -14,6 +14,7 @@
#define __LEDS_H_INCLUDED
#include <linux/device.h>
#include <linux/rwsem.h>
#include <linux/leds.h>
static inline void led_set_brightness(struct led_classdev *led_cdev,
@ -26,7 +27,7 @@ static inline void led_set_brightness(struct led_classdev *led_cdev,
led_cdev->brightness_set(led_cdev, value);
}
extern rwlock_t leds_list_lock;
extern struct rw_semaphore leds_list_lock;
extern struct list_head leds_list;
#ifdef CONFIG_LEDS_TRIGGERS