Input: gpio_keys - defer probing if GPIO probing is deferred

commit e324ce61 upstream.

If of_get_gpio_flags() returns an error (as in case when GPIO probe is
deferred) the driver would attempt to claim invalid GPIO. It should
propagate the error code up the stack instead so that the probe either
fails or will be retried later (in case of -EPROBE_DEFER).
Reported-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/input/keyboard/gpio_keys.c

@@ -587,6 +587,7 @@ gpio_keys_get_devtree_pdata(struct device *dev)
 
 	i = 0;
 	for_each_child_of_node(node, pp) {
+		int gpio;
 		enum of_gpio_flags flags;
 
 		if (!of_find_property(pp, "gpios", NULL)) {
@@ -595,9 +596,19 @@ gpio_keys_get_devtree_pdata(struct device *dev)
 			continue;
 		}
 
+		gpio = of_get_gpio_flags(pp, 0, &flags);
+		if (gpio < 0) {
+			error = gpio;
+			if (error != -EPROBE_DEFER)
+				dev_err(dev,
+					"Failed to get gpio flags, error: %d\n",
+					error);
+			goto err_free_pdata;
+		}
+
 		button = &pdata->buttons[i++];
 
-		button->gpio = of_get_gpio_flags(pp, 0, &flags);
+		button->gpio = gpio;
 		button->active_low = flags & OF_GPIO_ACTIVE_LOW;
 
 		if (of_property_read_u32(pp, "linux,code", &button->code)) {