Input: gpio_keys_polled - defer probing if GPIO probing is deferred

If GPIO probing is deferred, the driver tries to claim an invalid GPIO line
which leads to an error message like this:

  gpio-keys-polled buttons.2: unable to claim gpio 4294966779, err=-22
  gpio-keys-polled: probe of buttons.2 failed with error -22

We should make sure that error code returned by of_get_gpio_flags (including
-EPROBE_DEFER) is propagated up the stack.

Cc: stable@vger.kernel.org
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index f686fd9..2114716 100644 (file)
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -135,6 +135,7 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
 
        i = 0;
        for_each_child_of_node(node, pp) {
+               int gpio;
                enum of_gpio_flags flags;
 
                if (!of_find_property(pp, "gpios", NULL)) {
@@ -143,9 +144,19 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
                        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)) {