1 files changed, 109 insertions, 58 deletions

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 4e7b78a84149..3799dcc1cf07 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -23,7 +23,7 @@
  * Nests outside led_cdev->trigger_lock
  */
 static DECLARE_RWSEM(triggers_list_lock);
-LIST_HEAD(trigger_list);
+static LIST_HEAD(trigger_list);
 
  /* Used by LED Class */
 
@@ -34,7 +34,7 @@ trigger_relevant(struct led_classdev *led_cdev, struct led_trigger *trig)
 }
 
 ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
-			  struct bin_attribute *bin_attr, char *buf,
+			  const struct bin_attribute *bin_attr, char *buf,
 			  loff_t pos, size_t count)
 {
 	struct device *dev = kobj_to_dev(kobj);
@@ -54,6 +54,11 @@ ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
 		goto unlock;
 	}
 
+	if (sysfs_streq(buf, "default")) {
+		led_trigger_set_default(led_cdev);
+		goto unlock;
+	}
+
 	down_read(&triggers_list_lock);
 	list_for_each_entry(trig, &trigger_list, next_trig) {
 		if (sysfs_streq(buf, trig->name) && trigger_relevant(led_cdev, trig)) {
@@ -98,6 +103,9 @@ static int led_trigger_format(char *buf, size_t size,
 	int len = led_trigger_snprintf(buf, size, "%s",
 				       led_cdev->trigger ? "none" : "[none]");
 
+	if (led_cdev->default_trigger)
+		len += led_trigger_snprintf(buf + len, size - len, " default");
+
 	list_for_each_entry(trig, &trigger_list, next_trig) {
 		bool hit;
 
@@ -123,7 +131,7 @@ static int led_trigger_format(char *buf, size_t size,
  * copy it.
  */
 ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
-			struct bin_attribute *attr, char *buf,
+			const struct bin_attribute *attr, char *buf,
 			loff_t pos, size_t count)
 {
 	struct device *dev = kobj_to_dev(kobj);
@@ -157,7 +165,6 @@ EXPORT_SYMBOL_GPL(led_trigger_read);
 /* Caller must ensure led_cdev->trigger_lock held */
 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
 {
-	unsigned long flags;
 	char *event = NULL;
 	char *envp[2];
 	const char *name;
@@ -171,31 +178,48 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
 
 	/* Remove any existing trigger */
 	if (led_cdev->trigger) {
-		write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
-		list_del(&led_cdev->trig_list);
-		write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
-			flags);
+		spin_lock(&led_cdev->trigger->leddev_list_lock);
+		list_del_rcu(&led_cdev->trig_list);
+		spin_unlock(&led_cdev->trigger->leddev_list_lock);
+
+		/* ensure it's no longer visible on the led_cdevs list */
+		synchronize_rcu();
+
 		cancel_work_sync(&led_cdev->set_brightness_work);
 		led_stop_software_blink(led_cdev);
+		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
 		if (led_cdev->trigger->deactivate)
 			led_cdev->trigger->deactivate(led_cdev);
-		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
 		led_cdev->trigger = NULL;
 		led_cdev->trigger_data = NULL;
 		led_cdev->activated = false;
+		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
 		led_set_brightness(led_cdev, LED_OFF);
 	}
 	if (trig) {
-		write_lock_irqsave(&trig->leddev_list_lock, flags);
-		list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
-		write_unlock_irqrestore(&trig->leddev_list_lock, flags);
+		spin_lock(&trig->leddev_list_lock);
+		list_add_tail_rcu(&led_cdev->trig_list, &trig->led_cdevs);
+		spin_unlock(&trig->leddev_list_lock);
 		led_cdev->trigger = trig;
 
+		/*
+		 * Some activate() calls use led_trigger_event() to initialize
+		 * the brightness of the LED for which the trigger is being set.
+		 * Ensure the led_cdev is visible on trig->led_cdevs for this.
+		 */
+		synchronize_rcu();
+
+		/*
+		 * If "set brightness to 0" is pending in workqueue,
+		 * we don't want that to be reordered after ->activate()
+		 */
+		flush_work(&led_cdev->set_brightness_work);
+
+		ret = 0;
 		if (trig->activate)
 			ret = trig->activate(led_cdev);
 		else
-			ret = 0;
-
+			led_set_brightness(led_cdev, trig->brightness);
 		if (ret)
 			goto err_activate;
 
@@ -223,9 +247,10 @@ err_add_groups:
 		trig->deactivate(led_cdev);
 err_activate:
 
-	write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
-	list_del(&led_cdev->trig_list);
-	write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
+	spin_lock(&led_cdev->trigger->leddev_list_lock);
+	list_del_rcu(&led_cdev->trig_list);
+	spin_unlock(&led_cdev->trigger->leddev_list_lock);
+	synchronize_rcu();
 	led_cdev->trigger = NULL;
 	led_cdev->trigger_data = NULL;
 	led_set_brightness(led_cdev, LED_OFF);
@@ -243,40 +268,50 @@ void led_trigger_remove(struct led_classdev *led_cdev)
 }
 EXPORT_SYMBOL_GPL(led_trigger_remove);
 
+static bool led_match_default_trigger(struct led_classdev *led_cdev,
+				      struct led_trigger *trig)
+{
+	if (!strcmp(led_cdev->default_trigger, trig->name) &&
+	    trigger_relevant(led_cdev, trig)) {
+		led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
+		led_trigger_set(led_cdev, trig);
+		return true;
+	}
+
+	return false;
+}
+
 void led_trigger_set_default(struct led_classdev *led_cdev)
 {
 	struct led_trigger *trig;
+	bool found = false;
 
 	if (!led_cdev->default_trigger)
 		return;
 
+	if (!strcmp(led_cdev->default_trigger, "none")) {
+		led_trigger_remove(led_cdev);
+		return;
+	}
+
 	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) &&
-		    trigger_relevant(led_cdev, trig)) {
-			led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
-			led_trigger_set(led_cdev, trig);
+		found = led_match_default_trigger(led_cdev, trig);
+		if (found)
 			break;
-		}
 	}
 	up_write(&led_cdev->trigger_lock);
 	up_read(&triggers_list_lock);
-}
-EXPORT_SYMBOL_GPL(led_trigger_set_default);
-
-void led_trigger_rename_static(const char *name, struct led_trigger *trig)
-{
-	/* new name must be on a temporary string to prevent races */
-	BUG_ON(name == trig->name);
 
-	down_write(&triggers_list_lock);
-	/* this assumes that trig->name was originaly allocated to
-	 * non constant storage */
-	strcpy((char *)trig->name, name);
-	up_write(&triggers_list_lock);
+	/*
+	 * If default trigger wasn't found, maybe trigger module isn't loaded yet.
+	 * Once loaded it will re-probe with all led_cdev's.
+	 */
+	if (!found)
+		request_module_nowait("ledtrig:%s", led_cdev->default_trigger);
 }
-EXPORT_SYMBOL_GPL(led_trigger_rename_static);
+EXPORT_SYMBOL_GPL(led_trigger_set_default);
 
 /* LED Trigger Interface */
 
@@ -285,7 +320,7 @@ int led_trigger_register(struct led_trigger *trig)
 	struct led_classdev *led_cdev;
 	struct led_trigger *_trig;
 
-	rwlock_init(&trig->leddev_list_lock);
+	spin_lock_init(&trig->leddev_list_lock);
 	INIT_LIST_HEAD(&trig->led_cdevs);
 
 	down_write(&triggers_list_lock);
@@ -306,12 +341,8 @@ int led_trigger_register(struct led_trigger *trig)
 	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 &&
-		    !strcmp(led_cdev->default_trigger, trig->name) &&
-		    trigger_relevant(led_cdev, trig)) {
-			led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
-			led_trigger_set(led_cdev, trig);
-		}
+		if (!led_cdev->trigger && led_cdev->default_trigger)
+			led_match_default_trigger(led_cdev, trig);
 		up_write(&led_cdev->trigger_lock);
 	}
 	up_read(&leds_list_lock);
@@ -378,52 +409,72 @@ void led_trigger_event(struct led_trigger *trig,
 			enum led_brightness brightness)
 {
 	struct led_classdev *led_cdev;
-	unsigned long flags;
 
 	if (!trig)
 		return;
 
-	read_lock_irqsave(&trig->leddev_list_lock, flags);
-	list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
+	trig->brightness = brightness;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list)
 		led_set_brightness(led_cdev, brightness);
-	read_unlock_irqrestore(&trig->leddev_list_lock, flags);
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(led_trigger_event);
 
+void led_mc_trigger_event(struct led_trigger *trig,
+			  unsigned int *intensity_value, unsigned int num_colors,
+			  enum led_brightness brightness)
+{
+	struct led_classdev *led_cdev;
+
+	if (!trig)
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
+		if (!(led_cdev->flags & LED_MULTI_COLOR))
+			continue;
+
+		led_mc_set_brightness(led_cdev, intensity_value, num_colors, brightness);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(led_mc_trigger_event);
+
 static void led_trigger_blink_setup(struct led_trigger *trig,
-			     unsigned long *delay_on,
-			     unsigned long *delay_off,
+			     unsigned long delay_on,
+			     unsigned long delay_off,
 			     int oneshot,
 			     int invert)
 {
 	struct led_classdev *led_cdev;
-	unsigned long flags;
 
 	if (!trig)
 		return;
 
-	read_lock_irqsave(&trig->leddev_list_lock, flags);
-	list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
 		if (oneshot)
-			led_blink_set_oneshot(led_cdev, delay_on, delay_off,
+			led_blink_set_oneshot(led_cdev, &delay_on, &delay_off,
 					      invert);
 		else
-			led_blink_set(led_cdev, delay_on, delay_off);
+			led_blink_set_nosleep(led_cdev, delay_on, delay_off);
 	}
-	read_unlock_irqrestore(&trig->leddev_list_lock, flags);
+	rcu_read_unlock();
 }
 
 void led_trigger_blink(struct led_trigger *trig,
-		       unsigned long *delay_on,
-		       unsigned long *delay_off)
+		       unsigned long delay_on,
+		       unsigned long delay_off)
 {
 	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
 }
 EXPORT_SYMBOL_GPL(led_trigger_blink);
 
 void led_trigger_blink_oneshot(struct led_trigger *trig,
-			       unsigned long *delay_on,
-			       unsigned long *delay_off,
+			       unsigned long delay_on,
+			       unsigned long delay_off,
 			       int invert)
 {
 	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);