From 23ff2f0f6128b4c310fbb274dbb91cc2f9b6ab06 Mon Sep 17 00:00:00 2001 From: Charles Keepax Date: Wed, 14 Nov 2012 09:39:31 +0000 Subject: [PATCH] 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 Signed-off-by: Mark Brown --- drivers/regulator/core.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 5c4829c..3ebc06b 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -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(®ulator_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(®ulator_list_mutex); + _regulator_put(regulator); mutex_unlock(®ulator_list_mutex); } EXPORT_SYMBOL_GPL(regulator_put); @@ -3445,7 +3451,7 @@ unset_supplies: scrub: if (rdev->supply) - regulator_put(rdev->supply); + _regulator_put(rdev->supply); if (rdev->ena_gpio) gpio_free(rdev->ena_gpio); kfree(rdev->constraints); -- 2.7.4