leds: triggers: let struct led_trigger::activate() return an error code

Given that activating a trigger can fail, let the callback return an
indication. This prevents to have a trigger active according to the
"trigger" sysfs attribute but not functional.

All users are changed accordingly to return 0 for now. There is no intended
change in behaviour.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

3 files changed, 22 insertions, 8 deletions

diff --git a/net/bluetooth/leds.c b/net/bluetooth/leds.c
index cb670b5594eb..6d59a5023231 100644
--- a/net/bluetooth/leds.c
+++ b/net/bluetooth/leds.c
@@ -43,7 +43,7 @@ void hci_leds_update_powered(struct hci_dev *hdev, bool enabled)
 	led_trigger_event(bt_power_led_trigger, enabled ? LED_FULL : LED_OFF);
 }
 
-static void power_activate(struct led_classdev *led_cdev)
+static int power_activate(struct led_classdev *led_cdev)
 {
 	struct hci_basic_led_trigger *htrig;
 	bool powered;
@@ -52,10 +52,12 @@ static void power_activate(struct led_classdev *led_cdev)
 	powered = test_bit(HCI_UP, &htrig->hdev->flags);
 
 	led_trigger_event(led_cdev->trigger, powered ? LED_FULL : LED_OFF);
+
+	return 0;
 }
 
 static struct led_trigger *led_allocate_basic(struct hci_dev *hdev,
-			void (*activate)(struct led_classdev *led_cdev),
+			int (*activate)(struct led_classdev *led_cdev),
 			const char *name)
 {
 	struct hci_basic_led_trigger *htrig;
diff --git a/net/mac80211/led.c b/net/mac80211/led.c
index ba0b507ea691..d6c66fc19716 100644
--- a/net/mac80211/led.c
+++ b/net/mac80211/led.c
@@ -52,13 +52,15 @@ void ieee80211_free_led_names(struct ieee80211_local *local)
 	kfree(local->radio_led.name);
 }
 
-static void ieee80211_tx_led_activate(struct led_classdev *led_cdev)
+static int ieee80211_tx_led_activate(struct led_classdev *led_cdev)
 {
 	struct ieee80211_local *local = container_of(led_cdev->trigger,
 						     struct ieee80211_local,
 						     tx_led);
 
 	atomic_inc(&local->tx_led_active);
+
+	return 0;
 }
 
 static void ieee80211_tx_led_deactivate(struct led_classdev *led_cdev)
@@ -70,13 +72,15 @@ static void ieee80211_tx_led_deactivate(struct led_classdev *led_cdev)
 	atomic_dec(&local->tx_led_active);
 }
 
-static void ieee80211_rx_led_activate(struct led_classdev *led_cdev)
+static int ieee80211_rx_led_activate(struct led_classdev *led_cdev)
 {
 	struct ieee80211_local *local = container_of(led_cdev->trigger,
 						     struct ieee80211_local,
 						     rx_led);
 
 	atomic_inc(&local->rx_led_active);
+
+	return 0;
 }
 
 static void ieee80211_rx_led_deactivate(struct led_classdev *led_cdev)
@@ -88,13 +92,15 @@ static void ieee80211_rx_led_deactivate(struct led_classdev *led_cdev)
 	atomic_dec(&local->rx_led_active);
 }
 
-static void ieee80211_assoc_led_activate(struct led_classdev *led_cdev)
+static int ieee80211_assoc_led_activate(struct led_classdev *led_cdev)
 {
 	struct ieee80211_local *local = container_of(led_cdev->trigger,
 						     struct ieee80211_local,
 						     assoc_led);
 
 	atomic_inc(&local->assoc_led_active);
+
+	return 0;
 }
 
 static void ieee80211_assoc_led_deactivate(struct led_classdev *led_cdev)
@@ -106,13 +112,15 @@ static void ieee80211_assoc_led_deactivate(struct led_classdev *led_cdev)
 	atomic_dec(&local->assoc_led_active);
 }
 
-static void ieee80211_radio_led_activate(struct led_classdev *led_cdev)
+static int ieee80211_radio_led_activate(struct led_classdev *led_cdev)
 {
 	struct ieee80211_local *local = container_of(led_cdev->trigger,
 						     struct ieee80211_local,
 						     radio_led);
 
 	atomic_inc(&local->radio_led_active);
+
+	return 0;
 }
 
 static void ieee80211_radio_led_deactivate(struct led_classdev *led_cdev)
@@ -124,13 +132,15 @@ static void ieee80211_radio_led_deactivate(struct led_classdev *led_cdev)
 	atomic_dec(&local->radio_led_active);
 }
 
-static void ieee80211_tpt_led_activate(struct led_classdev *led_cdev)
+static int ieee80211_tpt_led_activate(struct led_classdev *led_cdev)
 {
 	struct ieee80211_local *local = container_of(led_cdev->trigger,
 						     struct ieee80211_local,
 						     tpt_led);
 
 	atomic_inc(&local->tpt_led_active);
+
+	return 0;
 }
 
 static void ieee80211_tpt_led_deactivate(struct led_classdev *led_cdev)
diff --git a/net/rfkill/core.c b/net/rfkill/core.c
index a7a4e6ff9be2..1355f5ca8d22 100644
--- a/net/rfkill/core.c
+++ b/net/rfkill/core.c
@@ -141,13 +141,15 @@ static void rfkill_led_trigger_event(struct rfkill *rfkill)
 		led_trigger_event(trigger, LED_FULL);
 }
 
-static void rfkill_led_trigger_activate(struct led_classdev *led)
+static int rfkill_led_trigger_activate(struct led_classdev *led)
 {
 	struct rfkill *rfkill;
 
 	rfkill = container_of(led->trigger, struct rfkill, led_trigger);
 
 	rfkill_led_trigger_event(rfkill);
+
+	return 0;
 }
 
 const char *rfkill_get_led_trigger_name(struct rfkill *rfkill)