Revert "rfkill: Add rfkill-any LED trigger"

This reverts commit 73f4f76a196d7adb11a1e192bd8024fe0bc83910.

As Mike reported, and I should've seen in review, we can't call
the new LED functions, which acquire the mutex, from places like
rfkill_set_sw_state() that are documented to be callable from
any context the user likes to use. For Mike's case it led to a
deadlock, but other scenarios are possible.

Reported-by: Михаил Кринкин <krinkin.m.u@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/rfkill/core.c

@@ -176,47 +176,6 @@ static void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 {
 	led_trigger_unregister(&rfkill->led_trigger);
 }
-
-static struct led_trigger rfkill_any_led_trigger;
-
-static void __rfkill_any_led_trigger_event(void)
-{
-	enum led_brightness brightness = LED_OFF;
-	struct rfkill *rfkill;
-
-	list_for_each_entry(rfkill, &rfkill_list, node) {
-		if (!(rfkill->state & RFKILL_BLOCK_ANY)) {
-			brightness = LED_FULL;
-			break;
-		}
-	}
-
-	led_trigger_event(&rfkill_any_led_trigger, brightness);
-}
-
-static void rfkill_any_led_trigger_event(void)
-{
-	mutex_lock(&rfkill_global_mutex);
-	__rfkill_any_led_trigger_event();
-	mutex_unlock(&rfkill_global_mutex);
-}
-
-static void rfkill_any_led_trigger_activate(struct led_classdev *led_cdev)
-{
-	rfkill_any_led_trigger_event();
-}
-
-static int rfkill_any_led_trigger_register(void)
-{
-	rfkill_any_led_trigger.name = "rfkill-any";
-	rfkill_any_led_trigger.activate = rfkill_any_led_trigger_activate;
-	return led_trigger_register(&rfkill_any_led_trigger);
-}
-
-static void rfkill_any_led_trigger_unregister(void)
-{
-	led_trigger_unregister(&rfkill_any_led_trigger);
-}
 #else
 static void rfkill_led_trigger_event(struct rfkill *rfkill)
 {
@@ -230,23 +189,6 @@ static inline int rfkill_led_trigger_register(struct rfkill *rfkill)
 static inline void rfkill_led_trigger_unregister(struct rfkill *rfkill)
 {
 }
-
-static void __rfkill_any_led_trigger_event(void)
-{
-}
-
-static void rfkill_any_led_trigger_event(void)
-{
-}
-
-static int rfkill_any_led_trigger_register(void)
-{
-	return 0;
-}
-
-static void rfkill_any_led_trigger_unregister(void)
-{
-}
 #endif /* CONFIG_RFKILL_LEDS */
 
 static void rfkill_fill_event(struct rfkill_event *ev, struct rfkill *rfkill,
@@ -355,7 +297,6 @@ static void rfkill_set_block(struct rfkill *rfkill, bool blocked)
 	spin_unlock_irqrestore(&rfkill->lock, flags);
 
 	rfkill_led_trigger_event(rfkill);
-	__rfkill_any_led_trigger_event();
 
 	if (prev != curr)
 		rfkill_event(rfkill);
@@ -536,7 +477,6 @@ bool rfkill_set_hw_state(struct rfkill *rfkill, bool blocked)
 	spin_unlock_irqrestore(&rfkill->lock, flags);
 
 	rfkill_led_trigger_event(rfkill);
-	rfkill_any_led_trigger_event();
 
 	if (rfkill->registered && prev != blocked)
 		schedule_work(&rfkill->uevent_work);
@@ -580,7 +520,6 @@ bool rfkill_set_sw_state(struct rfkill *rfkill, bool blocked)
 		schedule_work(&rfkill->uevent_work);
 
 	rfkill_led_trigger_event(rfkill);
-	rfkill_any_led_trigger_event();
 
 	return blocked;
 }
@@ -630,7 +569,6 @@ void rfkill_set_states(struct rfkill *rfkill, bool sw, bool hw)
 			schedule_work(&rfkill->uevent_work);
 
 		rfkill_led_trigger_event(rfkill);
-		rfkill_any_led_trigger_event();
 	}
 }
 EXPORT_SYMBOL(rfkill_set_states);
@@ -874,10 +812,8 @@ static int rfkill_resume(struct device *dev)
 	rfkill->suspended = false;
 
 	if (!rfkill->persistent) {
-		mutex_lock(&rfkill_global_mutex);
 		cur = !!(rfkill->state & RFKILL_BLOCK_SW);
 		rfkill_set_block(rfkill, cur);
-		mutex_unlock(&rfkill_global_mutex);
 	}
 
 	if (rfkill->ops->poll && !rfkill->polling_paused)
@@ -1049,7 +985,6 @@ int __must_check rfkill_register(struct rfkill *rfkill)
 #endif
 	}
 
-	__rfkill_any_led_trigger_event();
 	rfkill_send_events(rfkill, RFKILL_OP_ADD);
 
 	mutex_unlock(&rfkill_global_mutex);
@@ -1082,7 +1017,6 @@ void rfkill_unregister(struct rfkill *rfkill)
 	mutex_lock(&rfkill_global_mutex);
 	rfkill_send_events(rfkill, RFKILL_OP_DEL);
 	list_del_init(&rfkill->node);
-	__rfkill_any_led_trigger_event();
 	mutex_unlock(&rfkill_global_mutex);
 
 	rfkill_led_trigger_unregister(rfkill);
@@ -1335,10 +1269,6 @@ static int __init rfkill_init(void)
 	if (error)
 		goto error_misc;
 
-	error = rfkill_any_led_trigger_register();
-	if (error)
-		goto error_led_trigger;
-
 #ifdef CONFIG_RFKILL_INPUT
 	error = rfkill_handler_init();
 	if (error)
@@ -1349,10 +1279,8 @@ static int __init rfkill_init(void)
 
 #ifdef CONFIG_RFKILL_INPUT
 error_input:
-	rfkill_any_led_trigger_unregister();
-#endif
-error_led_trigger:
 	misc_deregister(&rfkill_miscdev);
+#endif
 error_misc:
 	class_unregister(&rfkill_class);
 error_class:
@@ -1365,7 +1293,6 @@ static void __exit rfkill_exit(void)
 #ifdef CONFIG_RFKILL_INPUT
 	rfkill_handler_exit();
 #endif
-	rfkill_any_led_trigger_unregister();
 	misc_deregister(&rfkill_miscdev);
 	class_unregister(&rfkill_class);
 }