gpiolib: check for parent device in devprop_gpiochip_set_names()

From: Bartosz Golaszewski <[email protected]>

It's possible for a GPIO chip to not have a parent device (whose properties we inspect for 'gpio-line-names'). In this case we should simply return from devprop_gpiochip_set_names(). Add an appropriate check for this use-case.

Fixes 7cba1a4d5e16 ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")

Reported-by Anders Roxell <[email protected]>

Signed-off-by Bartosz Golaszewski <[email protected]>

---
 drivers/gpio/gpiolib.c | 3 +++
 1 file changed, 3 insertions(+)

drivers/gpio/gpiolib.c +3 -0

index b7b608ef9..ac2c77edc 100644
@@ -375,6 +375,9 @@ static int devprop_gpiochip_set_names(struct gpio_chip *chip)
 	int ret, i;
 	int count;
 
+	if (!dev)
+		return 0;
+
 	count = device_property_string_array_count(dev, "gpio-line-names");
 	if (count < 0)
 		return 0;

Signature · 1 line

2.26.1

Quoted 6 lines · Bartosz Golaszewski

From: Bartosz Golaszewski <[email protected]>

It's possible for a GPIO chip to not have a parent device (whose properties we inspect for 'gpio-line-names'). In this case we should simply return from devprop_gpiochip_set_names(). Add an appropriate check for this use-case.

Ah, nice!
Can we also add a small comment in the code, b/c w/o it I would stumble over and eager to remove looks-as-unneeded check?

Reviewed-by Andy Shevchenko <[email protected]>

Quoted 9 lines · Andy Shevchenko

Quoted 6 lines · Bartosz Golaszewski

From: Bartosz Golaszewski <[email protected]>

It's possible for a GPIO chip to not have a parent device (whose properties we inspect for 'gpio-line-names'). In this case we should simply return from devprop_gpiochip_set_names(). Add an appropriate check for this use-case.

Quoted 4 lines

Ah, nice!
Can we also add a small comment in the code, b/c w/o it I would stumble over and eager to remove looks-as-unneeded check?

Reviewed-by Andy Shevchenko <[email protected]>