[PATCH] regulator: Fix deadlock on removal of regulators with supplies

From: Mark Brown
Date: Wed Mar 28 2012 - 16:19:35 EST


If a regulator with a supply is being unregistered we will call
regulator_put() to release the supply with the regulator_list_mutex held
but this deadlocks as regulator_put() takes the same lock. Fix this by
releasing the supply before we take the mutex in regulator_unregister().

Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
drivers/regulator/core.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 25d2b11..957f1d1 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2992,14 +2992,14 @@ void regulator_unregister(struct regulator_dev *rdev)
if (rdev == NULL)
return;

+ if (rdev->supply)
+ regulator_put(rdev->supply);
mutex_lock(&regulator_list_mutex);
debugfs_remove_recursive(rdev->debugfs);
flush_work_sync(&rdev->disable_work.work);
WARN_ON(rdev->open_count);
unset_regulator_supplies(rdev);
list_del(&rdev->list);
- if (rdev->supply)
- regulator_put(rdev->supply);
kfree(rdev->constraints);
device_unregister(&rdev->dev);
mutex_unlock(&regulator_list_mutex);
--
1.7.9.1

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