[PATCH 3.16 33/99] gpiolib: Fix return value of gpio_to_desc() stub if !GPIOLIB

[Ben Hutchings]

3.16.65-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

commit c5510b8dafce5f3f5a039c9b262ebcae0092c462 upstream.

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: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 include/linux/gpio/consumer.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -245,7 +245,7 @@ static inline int gpiod_to_irq(const str
 
 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)
 {