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Commit 23ff2f0f authored by Charles Keepax's avatar Charles Keepax Committed by Mark Brown
Browse files

regulator: core: Avoid deadlock when regulator_register fails 



When regulator_register fails and exits through the scrub path the
regulator_put function was called whilst holding the
regulator_list_mutex, causing deadlock.

This patch adds a private version of the regulator_put function which
can be safely called whilst holding the mutex, replacing the
aforementioned call.

Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 77b67063

drivers/regulator/core.c

+17 −11
Original line number Diff line number Diff line
@@ -1381,22 +1381,14 @@ struct regulator *regulator_get_exclusive(struct device *dev, const char *id) 
}

EXPORT_SYMBOL_GPL(regulator_get_exclusive);



/**

 * regulator_put - "free" the regulator source

 * @regulator: regulator source

 *

 * Note: drivers must ensure that all regulator_enable calls made on this

 * regulator source are balanced by regulator_disable calls prior to calling

 * this function.

 */

void regulator_put(struct regulator *regulator)

/* Locks held by regulator_put() */

static void _regulator_put(struct regulator *regulator)

{

	struct regulator_dev *rdev;



	if (regulator == NULL || IS_ERR(regulator))

		return;



	mutex_lock(&regulator_list_mutex);

	rdev = regulator->rdev;



	debugfs_remove_recursive(regulator->debugfs);
@@ -1412,6 +1404,20 @@ void regulator_put(struct regulator *regulator) 
	rdev->exclusive = 0;



	module_put(rdev->owner);

}



/**

 * regulator_put - "free" the regulator source

 * @regulator: regulator source

 *

 * Note: drivers must ensure that all regulator_enable calls made on this

 * regulator source are balanced by regulator_disable calls prior to calling

 * this function.

 */

void regulator_put(struct regulator *regulator)

{

	mutex_lock(&regulator_list_mutex);

	_regulator_put(regulator);

	mutex_unlock(&regulator_list_mutex);

}

EXPORT_SYMBOL_GPL(regulator_put);
@@ -3445,7 +3451,7 @@ regulator_register(const struct regulator_desc *regulator_desc, 


scrub:

	if (rdev->supply)

		regulator_put(rdev->supply);

		_regulator_put(rdev->supply);

	if (rdev->ena_gpio)

		gpio_free(rdev->ena_gpio);

	kfree(rdev->constraints);