[PATCH 4.19 171/190] gpio: dont WARN() on NULL descs if gpiolib is disabled

From: Greg Kroah-Hartman
Date: Fri Sep 13 2019 - 09:19:33 EST

[ Upstream commit ffe0bbabb0cffceceae07484fde1ec2a63b1537c ]

If gpiolib is disabled, we use the inline stubs from gpio/consumer.h
instead of regular definitions of GPIO API. The stubs for 'optional'
variants of gpiod_get routines return NULL in this case as if the
relevant GPIO wasn't found. This is correct so far.

Calling other (non-gpio_get) stubs from this header triggers a warning
because the GPIO descriptor couldn't have been requested. The warning
however is unconditional (WARN_ON(1)) and is emitted even if the passed
descriptor pointer is NULL.

We don't want to force the users of 'optional' gpio_get to check the
returned pointer before calling e.g. gpiod_set_value() so let's only
WARN on non-NULL descriptors.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Claus H. Stovgaard <cst@xxxxxxxxxxxx>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/linux/gpio/consumer.h | 62 +++++++++++++++++------------------
1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index acc4279ad5e3f..412098b24f58b 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -222,7 +222,7 @@ static inline void gpiod_put(struct gpio_desc *desc)
might_sleep();

/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
}

static inline void gpiod_put_array(struct gpio_descs *descs)
@@ -230,7 +230,7 @@ static inline void gpiod_put_array(struct gpio_descs *descs)
might_sleep();

/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(descs);
}

static inline struct gpio_desc *__must_check
@@ -283,7 +283,7 @@ static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
might_sleep();

/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
}

static inline void devm_gpiod_put_array(struct device *dev,
@@ -292,32 +292,32 @@ static inline void devm_gpiod_put_array(struct device *dev,
might_sleep();

/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(descs);
}


static inline int gpiod_get_direction(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -ENOSYS;
}
static inline int gpiod_direction_input(struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -ENOSYS;
}
static inline int gpiod_direction_output(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -ENOSYS;
}
static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -ENOSYS;
}

@@ -325,7 +325,7 @@ static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
static inline int gpiod_get_value(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return 0;
}
static inline int gpiod_get_array_value(unsigned int array_size,
@@ -333,25 +333,25 @@ static inline int gpiod_get_array_value(unsigned int array_size,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}
static inline void gpiod_set_value(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
}
static inline void gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
}
static inline int gpiod_get_raw_value(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return 0;
}
static inline int gpiod_get_raw_array_value(unsigned int array_size,
@@ -359,27 +359,27 @@ static inline int gpiod_get_raw_array_value(unsigned int array_size,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}
static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
}
static inline int gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}

static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return 0;
}
static inline int gpiod_get_array_value_cansleep(unsigned int array_size,
@@ -387,25 +387,25 @@ static inline int gpiod_get_array_value_cansleep(unsigned int array_size,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}
static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
}
static inline void gpiod_set_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
}
static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return 0;
}
static inline int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
@@ -413,55 +413,55 @@ static inline int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}
static inline void gpiod_set_raw_value_cansleep(struct gpio_desc *desc,
int value)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
}
static inline int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}

static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -ENOSYS;
}

static inline int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -ENOSYS;
}

static inline int gpiod_is_active_low(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return 0;
}
static inline int gpiod_cansleep(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return 0;
}

static inline int gpiod_to_irq(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -EINVAL;
}

@@ -469,7 +469,7 @@ static inline int gpiod_set_consumer_name(struct gpio_desc *desc,
const char *name)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -EINVAL;
}

@@ -481,7 +481,7 @@ static inline struct gpio_desc *gpio_to_desc(unsigned gpio)
static inline int desc_to_gpio(const struct gpio_desc *desc)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -EINVAL;
}

--
2.20.1