[PATCH] 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

The patch ensures that 'gpio_keys_polled_get_devtree_pdata'
returns -EPROBE_DEFER if any of the GPIOs to register are
deferred.

Cc: <redacted>
Signed-off-by: Gabor Juhos <redacted>
---
 drivers/input/keyboard/gpio_keys_polled.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index f686fd9..cfb54cc 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c

@@ -120,6 +120,12 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct
 	if (nbuttons == 0)
 		return NULL;
 
+	for_each_child_of_node(node, pp) {
+		error = of_get_gpio(pp, 0);
+		if (error == -EPROBE_DEFER)
+			goto err_out;
+	}
+
 	pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
 			GFP_KERNEL);
 	if (!pdata) {

-- 

Well spotted, thanks. However I think the patch should look like the one
below as we should propagate all errors, not only -EPROBE_DEFER, up the
stack.

Thanks.


Input: gpio_keys_polled - defer probing if GPIO probing is deferred

From: Gabor Juhos <redacted>

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

The patch ensures 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 <redacted>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/keyboard/gpio_keys_polled.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index f686fd9..e75ca6b 100644
--- 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)) {