LED trigger support fixes.
Split the locking on struct led_classdev into LED and trigger sections
to prevent potential deadlock.
Fix a bug introduced in -mm where leds.h can be included more than
once causing compile errors.
Make use of class_get_devdata()
Signed-off-by: Richard Purdie <[email protected]>
Index: linux-2.6.15/drivers/leds/led-class.c
===================================================================
--- linux-2.6.15.orig/drivers/leds/led-class.c 2006-02-08 01:20:41.000000000 +0000
+++ linux-2.6.15/drivers/leds/led-class.c 2006-02-08 01:20:51.000000000 +0000
@@ -106,18 +106,20 @@
class_device_create_file(led_cdev->class_dev,
&class_device_attr_brightness);
-#ifdef CONFIG_LEDS_TRIGGERS
- class_device_create_file(led_cdev->class_dev,
- &class_device_attr_trigger);
-#endif
-
/* add to the list of leds */
write_lock(&leds_list_lock);
list_add_tail(&led_cdev->node, &leds_list);
write_unlock(&leds_list_lock);
+#ifdef CONFIG_LEDS_TRIGGERS
+ rwlock_init(&led_cdev->trigger_lock);
+
led_trigger_set_default(led_cdev);
+ class_device_create_file(led_cdev->class_dev,
+ &class_device_attr_trigger);
+#endif
+
printk(KERN_INFO "Registered led device: %s\n",
led_cdev->class_dev->class_id);
@@ -138,10 +140,12 @@
#ifdef CONFIG_LEDS_TRIGGERS
class_device_remove_file(led_cdev->class_dev,
&class_device_attr_trigger);
-#endif
+ write_lock(&led_cdev->trigger_lock);
if (led_cdev->trigger)
led_trigger_set(led_cdev, NULL);
+ write_unlock(&led_cdev->trigger_lock);
+#endif
class_device_unregister(led_cdev->class_dev);
Index: linux-2.6.15/drivers/leds/led-triggers.c
===================================================================
--- linux-2.6.15.orig/drivers/leds/led-triggers.c 2006-02-08 01:20:50.000000000 +0000
+++ linux-2.6.15/drivers/leds/led-triggers.c 2006-02-08 01:20:51.000000000 +0000
@@ -24,7 +24,7 @@
#include "leds.h"
/*
- * Nests outside led_cdev->lock
+ * Nests outside led_cdev->lock and led_cdev->trigger_lock
*/
static rwlock_t triggers_list_lock = RW_LOCK_UNLOCKED;
static LIST_HEAD(trigger_list);
@@ -32,7 +32,7 @@
ssize_t led_trigger_store(struct class_device *dev, const char *buf,
size_t count)
{
- struct led_classdev *led_cdev = dev->class_data;
+ struct led_classdev *led_cdev = class_get_devdata(dev);
char trigger_name[TRIG_NAME_MAX];
struct led_trigger *trig;
size_t len;
@@ -45,18 +45,18 @@
trigger_name[len - 1] = '\0';
if (!strcmp(trigger_name, "none")) {
- write_lock(&led_cdev->lock);
+ write_lock(&led_cdev->trigger_lock);
led_trigger_set(led_cdev, NULL);
- write_unlock(&led_cdev->lock);
+ write_unlock(&led_cdev->trigger_lock);
return count;
}
read_lock(&triggers_list_lock);
list_for_each_entry(trig, &trigger_list, next_trig) {
if (!strcmp(trigger_name, trig->name)) {
- write_lock(&led_cdev->lock);
+ write_lock(&led_cdev->trigger_lock);
led_trigger_set(led_cdev, trig);
- write_unlock(&led_cdev->lock);
+ write_unlock(&led_cdev->trigger_lock);
read_unlock(&triggers_list_lock);
return count;
@@ -70,12 +70,12 @@
ssize_t led_trigger_show(struct class_device *dev, char *buf)
{
- struct led_classdev *led_cdev = dev->class_data;
+ struct led_classdev *led_cdev = class_get_devdata(dev);
struct led_trigger *trig;
int len = 0;
read_lock(&triggers_list_lock);
- read_lock(&led_cdev->lock);
+ read_lock(&led_cdev->trigger_lock);
if (!led_cdev->trigger)
len += sprintf(buf+len, "[none] ");
@@ -89,7 +89,7 @@
else
len += sprintf(buf+len, "%s ", trig->name);
}
- read_unlock(&led_cdev->lock);
+ read_unlock(&led_cdev->trigger_lock);
read_unlock(&triggers_list_lock);
len += sprintf(len+buf, "\n");
@@ -116,7 +116,7 @@
read_unlock(&trigger->leddev_list_lock);
}
-/* Caller must ensure led_cdev->lock held for write */
+/* Caller must ensure led_cdev->trigger_lock held */
void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
{
/* Remove any existing trigger */
@@ -126,7 +126,6 @@
write_unlock(&led_cdev->trigger->leddev_list_lock);
if (led_cdev->trigger->deactivate)
led_cdev->trigger->deactivate(led_cdev);
-
}
if (trigger) {
write_lock(&trigger->leddev_list_lock);
@@ -146,12 +145,12 @@
return;
read_lock(&triggers_list_lock);
- write_lock(&led_cdev->lock);
+ write_lock(&led_cdev->trigger_lock);
list_for_each_entry(trig, &trigger_list, next_trig) {
if (!strcmp(led_cdev->default_trigger, trig->name))
led_trigger_set(led_cdev, trig);
}
- write_unlock(&led_cdev->lock);
+ write_unlock(&led_cdev->trigger_lock);
read_unlock(&triggers_list_lock);
}
@@ -170,11 +169,11 @@
/* Register with any LEDs that have this as a default trigger */
read_lock(&leds_list_lock);
list_for_each_entry(led_cdev, &leds_list, node) {
- write_lock(&led_cdev->lock);
+ write_lock(&led_cdev->trigger_lock);
if (!led_cdev->trigger && led_cdev->default_trigger &&
!strcmp(led_cdev->default_trigger, trigger->name))
led_trigger_set(led_cdev, trigger);
- write_unlock(&led_cdev->lock);
+ write_unlock(&led_cdev->trigger_lock);
}
read_unlock(&leds_list_lock);
@@ -206,10 +205,10 @@
/* Remove anyone actively using this trigger */
read_lock(&leds_list_lock);
list_for_each_entry(led_cdev, &leds_list, node) {
- write_lock(&led_cdev->lock);
+ write_lock(&led_cdev->trigger_lock);
if (led_cdev->trigger == trigger)
led_trigger_set(led_cdev, NULL);
- write_unlock(&led_cdev->lock);
+ write_unlock(&led_cdev->trigger_lock);
}
read_unlock(&leds_list_lock);
}
Index: linux-2.6.15/include/linux/leds.h
===================================================================
--- linux-2.6.15.orig/include/linux/leds.h 2006-02-08 01:20:41.000000000 +0000
+++ linux-2.6.15/include/linux/leds.h 2006-02-08 01:21:54.000000000 +0000
@@ -10,6 +10,9 @@
*
*/
+#ifndef _LINUX_LEDS
+#define _LINUX_LEDS
+
struct device;
struct class_device;
/*
@@ -36,16 +39,19 @@
/* LED Device linked list */
struct list_head node;
+ /* Protects the LED properties data above */
+ rwlock_t lock;
+
/* Trigger data */
char *default_trigger;
#ifdef CONFIG_LEDS_TRIGGERS
+ rwlock_t trigger_lock;
+ /* Protects the trigger data below */
+
struct led_trigger *trigger;
struct list_head trig_list;
void *trigger_data;
#endif
-
- /* This protects the data in this structure */
- rwlock_t lock;
};
extern int led_classdev_register(struct device *parent,
@@ -98,3 +104,5 @@
#define led_trigger_event(x, y) do {} while(0)
#endif
+
+#endif /* _LINUX_LEDS */
-
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