gpiolib: Initialize gdev field before is used

mainline inclusion
from mainline-v4.20-rc1
commit 767cd17a
category: bugfix
bugzilla: 14225
CVE: NA

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

gpio_hog depends on gdev field being initialized. This patch fixes an
OOPs during initialization of TI's AM335x-ICEv2.

Fixes: 3edfb7bd ("gpiolib: Show correct direction from the beginning")
Tested-by: NVignesh R <vigneshr@ti.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/gpio/gpiolib.c

@@ -1361,6 +1361,9 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
+	for (i = 0; i < chip->ngpio; i++)
+		gdev->descs[i].gdev = gdev;
+
 #ifdef CONFIG_PINCTRL
 	INIT_LIST_HEAD(&gdev->pin_ranges);
 #endif
@@ -1392,8 +1395,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 	for (i = 0; i < chip->ngpio; i++) {
 		struct gpio_desc *desc = &gdev->descs[i];
 
-		desc->gdev = gdev;
-
 		if (chip->get_direction && gpiochip_line_is_valid(chip, i))
 			desc->flags = !chip->get_direction(chip, i) ?
 					(1 << FLAG_IS_OUT) : 0;