Commit 5f402bb1 authored by Ahmad Fatoum's avatar Ahmad Fatoum Committed by Linus Walleij
Browse files

gpio: don't use same lockdep class for all devm_gpiochip_add_data users 



Commit 959bc7b2 ("gpio: Automatically add lockdep keys") documents
in its commits message its intention to "create a unique class key for
each driver".

It does so by having gpiochip_add_data add in-place the definition of
two static lockdep classes for LOCKDEP use. That way, every caller of
the macro adds their gpiochip with unique lockdep classes.

There are many indirect callers of gpiochip_add_data, however, via
use of devm_gpiochip_add_data. devm_gpiochip_add_data has external
linkage and all its users will share the same lockdep classes, which
probably is not intended.

Fix this by replicating the gpio_chip_add_data statics-in-macro for
the devm_ version as well.

Fixes: 959bc7b2 ("gpio: Automatically add lockdep keys")
Signed-off-by: default avatarAhmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200731123835.8003-1-a.fatoum@pengutronix.de


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent bb58a47a

drivers/gpio/gpiolib-devres.c

+8 −5
Original line number Diff line number Diff line
@@ -487,10 +487,12 @@ static void devm_gpio_chip_release(struct device *dev, void *res) 
}



/**

 * devm_gpiochip_add_data() - Resource managed gpiochip_add_data()

 * devm_gpiochip_add_data_with_key() - Resource managed gpiochip_add_data_with_key()

 * @dev: pointer to the device that gpio_chip belongs to.

 * @gc: the GPIO chip to register

 * @data: driver-private data associated with this chip

 * @lock_key: lockdep class for IRQ lock

 * @request_key: lockdep class for IRQ request

 *

 * Context: potentially before irqs will work

 *
@@ -501,8 +503,9 @@ static void devm_gpio_chip_release(struct device *dev, void *res) 
 * gc->base is invalid or already associated with a different chip.

 * Otherwise it returns zero as a success code.

 */

int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *gc,

			   void *data)

int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc, void *data,

				    struct lock_class_key *lock_key,

				    struct lock_class_key *request_key)

{

	struct gpio_chip **ptr;

	int ret;
@@ -512,7 +515,7 @@ int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *gc, 
	if (!ptr)

		return -ENOMEM;



	ret = gpiochip_add_data(gc, data);

	ret = gpiochip_add_data_with_key(gc, data, lock_key, request_key);

	if (ret < 0) {

		devres_free(ptr);

		return ret;
@@ -523,4 +526,4 @@ int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *gc, 


	return 0;

}

EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
 
EXPORT_SYMBOL_GPL(devm_gpiochip_add_data_with_key);

include/linux/gpio/driver.h

+11 −2
Original line number Diff line number Diff line
@@ -525,8 +525,16 @@ extern int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
		gpiochip_add_data_with_key(gc, data, &lock_key, \

					   &request_key);	  \

	})

#define devm_gpiochip_add_data(dev, gc, data) ({ \

		static struct lock_class_key lock_key;	\

		static struct lock_class_key request_key;	  \

		devm_gpiochip_add_data_with_key(dev, gc, data, &lock_key, \

					   &request_key);	  \

	})

#else

#define gpiochip_add_data(gc, data) gpiochip_add_data_with_key(gc, data, NULL, NULL)

#define devm_gpiochip_add_data(dev, gc, data) \

	devm_gpiochip_add_data_with_key(dev, gc, data, NULL, NULL)

#endif /* CONFIG_LOCKDEP */



static inline int gpiochip_add(struct gpio_chip *gc)
@@ -534,8 +542,9 @@ static inline int gpiochip_add(struct gpio_chip *gc) 
	return gpiochip_add_data(gc, NULL);

}

extern void gpiochip_remove(struct gpio_chip *gc);

extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *gc,

				  void *data);

extern int devm_gpiochip_add_data_with_key(struct device *dev, struct gpio_chip *gc, void *data,

					   struct lock_class_key *lock_key,

					   struct lock_class_key *request_key);



extern struct gpio_chip *gpiochip_find(void *data,

			      int (*match)(struct gpio_chip *gc, void *data));

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