3.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

commit e324ce61ef483dd26d03502d35666ad48a2e1b33 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 <redacted>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/input/keyboard/gpio_keys.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c

@@ -587,6 +587,7 @@ gpio_keys_get_devtree_pdata(struct devic
 
 	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 devic
 			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)) {