[PATCH 5.2 088/131] gpio: dont WARN() on NULL descs if gpiolib is disabled

From: Greg Kroah-Hartman
Date: Mon Aug 05 2019 - 09:24:02 EST


From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

commit ffe0bbabb0cffceceae07484fde1ec2a63b1537c upstream.

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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
include/linux/gpio/consumer.h | 64 +++++++++++++++++++++---------------------
1 file changed, 32 insertions(+), 32 deletions(-)

--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -247,7 +247,7 @@ static inline void gpiod_put(struct gpio
might_sleep();

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

static inline void devm_gpiod_unhinge(struct device *dev,
@@ -256,7 +256,7 @@ static inline void devm_gpiod_unhinge(st
might_sleep();

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

static inline void gpiod_put_array(struct gpio_descs *descs)
@@ -264,7 +264,7 @@ static inline void gpiod_put_array(struc
might_sleep();

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

static inline struct gpio_desc *__must_check
@@ -317,7 +317,7 @@ static inline void devm_gpiod_put(struct
might_sleep();

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

static inline void devm_gpiod_put_array(struct device *dev,
@@ -326,32 +326,32 @@ static inline void devm_gpiod_put_array(
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;
}

@@ -359,7 +359,7 @@ static inline int gpiod_direction_output
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,
@@ -368,13 +368,13 @@ static inline int gpiod_get_array_value(
unsigned long *value_bitmap)
{
/* 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 int gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
@@ -382,13 +382,13 @@ static inline int gpiod_set_array_value(
unsigned long *value_bitmap)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}
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,
@@ -397,13 +397,13 @@ static inline int gpiod_get_raw_array_va
unsigned long *value_bitmap)
{
/* 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,
@@ -411,14 +411,14 @@ static inline int gpiod_set_raw_array_va
unsigned long *value_bitmap)
{
/* 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,
@@ -427,13 +427,13 @@ static inline int gpiod_get_array_value_
unsigned long *value_bitmap)
{
/* 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 int gpiod_set_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
@@ -441,13 +441,13 @@ static inline int gpiod_set_array_value_
unsigned long *value_bitmap)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc_array);
return 0;
}
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,
@@ -456,14 +456,14 @@ static inline int gpiod_get_raw_array_va
unsigned long *value_bitmap)
{
/* 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,
@@ -471,41 +471,41 @@ static inline int gpiod_set_raw_array_va
unsigned long *value_bitmap)
{
/* 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;
}

@@ -513,7 +513,7 @@ static inline int gpiod_set_consumer_nam
const char *name)
{
/* GPIO can never have been requested */
- WARN_ON(1);
+ WARN_ON(desc);
return -EINVAL;
}

@@ -525,7 +525,7 @@ static inline struct gpio_desc *gpio_to_
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;
}