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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: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Charles Keepax 2012-11-14 09:39:31 +00:00 committed by Mark Brown
parent 77b67063bb
commit 23ff2f0f61
1 changed files with 17 additions and 11 deletions
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28
drivers/regulator/core.c
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@ -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);