gpiolib: Fix of_node inconsistency

Some platforms are not setting of_node in the driver. On these platforms
defining gpio-reserved-ranges on device tree leads to kernel crash.

It is due to some parts of the gpio core relying on the driver to set up
of_node,while other parts do themselves.This inconsistent behaviour leads
to a crash.

gpiochip_add_data_with_key() calls gpiochip_init_valid_mask() with of_node
as NULL. of_gpiochip_add() fills "of_node" and calls
of_gpiochip_init_valid_mask().

The fix is to move the assignment to chip->of_node from of_gpiochip_add()
to gpiochip_add_data_with_key().

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

2 files changed, 2 insertions, 3 deletions

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 28d968088131..91174bf15cf3 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -620,9 +620,6 @@ int of_gpiochip_add(struct gpio_chip *chip)
 {
         int status;
 
-        if ((!chip->of_node) && (chip->parent))
-                chip->of_node = chip->parent->of_node;
-
         if (!chip->of_node)
                 return 0;
 
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6bfd4e5cc161..2c457e604403 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1262,6 +1262,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
         /* If the gpiochip has an assigned OF node this takes precedence */
         if (chip->of_node)
                 gdev->dev.of_node = chip->of_node;
+        else
+                chip->of_node = gdev->dev.of_node;
 #endif
 
         gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);