[PATCH 4/4] led: gpio: Properly deal with deferred probing

[Sebastian Hesselbarth]

GPIO LEDs can suffer from deferred probing due to failing gpio request.
If of_get_named_gpio_flags returns -EPROBE_DEFER, skip current LED and
request deferred probing later. Since not all LEDs have to fail, build
a mask of already registered LEDs to be skipped later on deferred probe.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
---
Cc: barebox at lists.infradead.org
---
 drivers/led/led-gpio.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
index ae3f13f45b6c..91e5d5b76085 100644
--- a/drivers/led/led-gpio.c
+++ b/drivers/led/led-gpio.c
@@ -201,6 +201,8 @@ void led_gpio_rgb_unregister(struct gpio_led *led)
 static int led_gpio_of_probe(struct device_d *dev)
 {
 	struct device_node *child;
+	static u32 registered;
+	int ret = 0, n = 0;
 
 	for_each_child_of_node(dev->device_node, child) {
 		struct gpio_led *gled;
@@ -209,7 +211,15 @@ static int led_gpio_of_probe(struct device_d *dev)
 		int gpio;
 		const char *label;
 
+		/* On deferred probing, skip already registered LEDs */
+		if (registered & BIT(n)) {
+			n++;
+			continue;
+		}
+
 		gpio = of_get_named_gpio_flags(child, "gpios", 0, &flags);
+		if (gpio == -EPROBE_DEFER)
+			ret = -EPROBE_DEFER;
 		if (gpio < 0)
 			continue;
 
@@ -233,9 +243,12 @@ static int led_gpio_of_probe(struct device_d *dev)
 			else if (!strcmp(default_state, "off"))
 				led_gpio_set(&gled->led, 0);
 		}
+
+		registered |= BIT(n);
+		n++;
 	}
 
-	return 0;
+	return ret;
 }
 
 static struct of_device_id led_gpio_of_ids[] = {
-- 
2.1.0