leds: Fix led trigger locking bugs

[linux-2.6-omap-h63xx.git] / drivers / leds / led-triggers.c

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 47f0ff196328d2808268a17701444b08faafee1a..0bdb786210b1885bee8e6f194ccdcab09e5bdd18 100644 (file)
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -1,7 +1,7 @@
 /*
  * LED Triggers Core
  *
- * Copyright 2005-2006 Openedhand Ltd.
+ * Copyright 2005-2007 Openedhand Ltd.
  *
  * Author: Richard Purdie <rpurdie@openedhand.com>
  *
@@ -19,19 +19,20 @@
 #include <linux/device.h>
 #include <linux/sysdev.h>
 #include <linux/timer.h>
+#include <linux/rwsem.h>
 #include <linux/leds.h>
 #include "leds.h"
 
 /*
  * Nests outside led_cdev->trigger_lock
  */
-static DEFINE_RWLOCK(triggers_list_lock);
+static DECLARE_RWSEM(triggers_list_lock);
 static LIST_HEAD(trigger_list);
 
-ssize_t led_trigger_store(struct class_device *dev, const char *buf,
-                       size_t count)
+ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
+               const char *buf, size_t count)
 {
-       struct led_classdev *led_cdev = class_get_devdata(dev);
+       struct led_classdev *led_cdev = dev_get_drvdata(dev);
        char trigger_name[TRIG_NAME_MAX];
        struct led_trigger *trig;
        size_t len;
@@ -44,37 +45,38 @@ ssize_t led_trigger_store(struct class_device *dev, const char *buf,
                trigger_name[len - 1] = '\0';
 
        if (!strcmp(trigger_name, "none")) {
-               write_lock(&led_cdev->trigger_lock);
+               down_write(&led_cdev->trigger_lock);
                led_trigger_set(led_cdev, NULL);
-               write_unlock(&led_cdev->trigger_lock);
+               up_write(&led_cdev->trigger_lock);
                return count;
        }
 
-       read_lock(&triggers_list_lock);
+       down_read(&triggers_list_lock);
        list_for_each_entry(trig, &trigger_list, next_trig) {
                if (!strcmp(trigger_name, trig->name)) {
-                       write_lock(&led_cdev->trigger_lock);
+                       down_write(&led_cdev->trigger_lock);
                        led_trigger_set(led_cdev, trig);
-                       write_unlock(&led_cdev->trigger_lock);
+                       up_write(&led_cdev->trigger_lock);
 
-                       read_unlock(&triggers_list_lock);
+                       up_read(&triggers_list_lock);
                        return count;
                }
        }
-       read_unlock(&triggers_list_lock);
+       up_read(&triggers_list_lock);
 
        return -EINVAL;
 }
 
 
-ssize_t led_trigger_show(struct class_device *dev, char *buf)
+ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
+               char *buf)
 {
-       struct led_classdev *led_cdev = class_get_devdata(dev);
+       struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_trigger *trig;
        int len = 0;
 
-       read_lock(&triggers_list_lock);
-       read_lock(&led_cdev->trigger_lock);
+       down_read(&triggers_list_lock);
+       down_read(&led_cdev->trigger_lock);
 
        if (!led_cdev->trigger)
                len += sprintf(buf+len, "[none] ");
@@ -88,8 +90,8 @@ ssize_t led_trigger_show(struct class_device *dev, char *buf)
                else
                        len += sprintf(buf+len, "%s ", trig->name);
        }
-       read_unlock(&led_cdev->trigger_lock);
-       read_unlock(&triggers_list_lock);
+       up_read(&led_cdev->trigger_lock);
+       up_read(&triggers_list_lock);
 
        len += sprintf(len+buf, "\n");
        return len;
@@ -125,6 +127,7 @@ void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
                write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
                if (led_cdev->trigger->deactivate)
                        led_cdev->trigger->deactivate(led_cdev);
+               led_set_brightness(led_cdev, LED_OFF);
        }
        if (trigger) {
                write_lock_irqsave(&trigger->leddev_list_lock, flags);
@@ -143,14 +146,14 @@ void led_trigger_set_default(struct led_classdev *led_cdev)
        if (!led_cdev->default_trigger)
                return;
 
-       read_lock(&triggers_list_lock);
-       write_lock(&led_cdev->trigger_lock);
+       down_read(&triggers_list_lock);
+       down_write(&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->trigger_lock);
-       read_unlock(&triggers_list_lock);
+       up_write(&led_cdev->trigger_lock);
+       up_read(&triggers_list_lock);
 }
 
 int led_trigger_register(struct led_trigger *trigger)
@@ -161,18 +164,18 @@ int led_trigger_register(struct led_trigger *trigger)
        INIT_LIST_HEAD(&trigger->led_cdevs);
 
        /* Add to the list of led triggers */
-       write_lock(&triggers_list_lock);
+       down_write(&triggers_list_lock);
        list_add_tail(&trigger->next_trig, &trigger_list);
-       write_unlock(&triggers_list_lock);
+       up_write(&triggers_list_lock);
 
        /* 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->trigger_lock);
+               down_write(&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->trigger_lock);
+               up_write(&led_cdev->trigger_lock);
        }
        read_unlock(&leds_list_lock);
 
@@ -182,13 +185,20 @@ int led_trigger_register(struct led_trigger *trigger)
 void led_trigger_register_simple(const char *name, struct led_trigger **tp)
 {
        struct led_trigger *trigger;
+       int err;
 
        trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
 
        if (trigger) {
                trigger->name = name;
-               led_trigger_register(trigger);
-       }
+               err = led_trigger_register(trigger);
+               if (err < 0)
+                       printk(KERN_WARNING "LED trigger %s failed to register"
+                               " (%d)\n", name, err);
+       } else
+               printk(KERN_WARNING "LED trigger %s failed to register"
+                       " (no memory)\n", name);
+
        *tp = trigger;
 }
 
@@ -197,24 +207,25 @@ void led_trigger_unregister(struct led_trigger *trigger)
        struct led_classdev *led_cdev;
 
        /* Remove from the list of led triggers */
-       write_lock(&triggers_list_lock);
+       down_write(&triggers_list_lock);
        list_del(&trigger->next_trig);
-       write_unlock(&triggers_list_lock);
+       up_write(&triggers_list_lock);
 
        /* Remove anyone actively using this trigger */
        read_lock(&leds_list_lock);
        list_for_each_entry(led_cdev, &leds_list, node) {
-               write_lock(&led_cdev->trigger_lock);
+               down_write(&led_cdev->trigger_lock);
                if (led_cdev->trigger == trigger)
                        led_trigger_set(led_cdev, NULL);
-               write_unlock(&led_cdev->trigger_lock);
+               up_write(&led_cdev->trigger_lock);
        }
        read_unlock(&leds_list_lock);
 }
 
 void led_trigger_unregister_simple(struct led_trigger *trigger)
 {
-       led_trigger_unregister(trigger);
+       if (trigger)
+               led_trigger_unregister(trigger);
        kfree(trigger);
 }