[PATCH AUTOSEL 4.4 19/68] gpiolib: Fix return value of gpio_to_desc() stub if !GPIOLIB

[Sasha Levin]

From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

[ Upstream commit c5510b8dafce5f3f5a039c9b262ebcae0092c462 ]

If CONFIG_GPOILIB is not set, the stub of gpio_to_desc() should return
the same type of error as regular version: NULL.  All the callers
compare the return value of gpio_to_desc() against NULL, so returned
ERR_PTR would be treated as non-error case leading to dereferencing of
error value.

Fixes: 79a9becda894 ("gpiolib: export descriptor-based GPIO interface")
Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 include/linux/gpio/consumer.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index fb0fde686cb1f..4a9838feb0866 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -398,7 +398,7 @@ static inline int gpiod_to_irq(const struct gpio_desc *desc)
 
 static inline struct gpio_desc *gpio_to_desc(unsigned gpio)
 {
-	return ERR_PTR(-EINVAL);
+	return NULL;
 }
 
 static inline int desc_to_gpio(const struct gpio_desc *desc)
-- 
2.20.1