Commit 4dee0606 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'leds-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds 

Pull LED updates from Pavel Machek:
 "Johannes pointed out that locking is still problematic with triggers
  list, attempt to solve that by using RCU"

* tag 'leds-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds:
  leds: trigger: Disable CPU trigger on PREEMPT_RT
  leds: trigger: use RCU to protect the led_cdevs list
  led-class-flash: fix -Wrestrict warning
parents 73d21a35 97b31c1f

drivers/leds/led-class-flash.c

+1 −1
Original line number Diff line number Diff line
@@ -207,7 +207,7 @@ static ssize_t flash_fault_show(struct device *dev, 
		mask <<= 1;

	}



	return sprintf(buf, "%s\n", buf);

	return strlen(strcat(buf, "\n"));

}

static DEVICE_ATTR_RO(flash_fault);

drivers/leds/led-triggers.c

+21 −20
Original line number Diff line number Diff line
@@ -157,7 +157,6 @@ 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;
@@ -171,10 +170,13 @@ 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);

		if (led_cdev->trigger->deactivate)
@@ -186,9 +188,9 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig) 
		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;



		if (trig->activate)
@@ -223,9 +225,10 @@ int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig) 
		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);
@@ -285,7 +288,7 @@ 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);
@@ -378,15 +381,14 @@ 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)

	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);
@@ -397,20 +399,19 @@ static void led_trigger_blink_setup(struct led_trigger *trig, 
			     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,

					      invert);

		else

			led_blink_set(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,

drivers/leds/trigger/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ config LEDS_TRIGGER_BACKLIGHT 


config LEDS_TRIGGER_CPU

	bool "LED CPU Trigger"

	depends on !PREEMPT_RT

	help

	  This allows LEDs to be controlled by active CPUs. This shows

	  the active CPUs across an array of LEDs so you can see which

include/linux/leds.h

+1 −1
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ struct led_trigger { 
	struct led_hw_trigger_type *trigger_type;



	/* LEDs under control by this trigger (for simple triggers) */

	rwlock_t	  leddev_list_lock;

	spinlock_t	  leddev_list_lock;

	struct list_head  led_cdevs;



	/* Link to next registered trigger */