From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Date: Wed, 28 Mar 2012 20:17:55 +0000 (+0100)
Subject: regulator: Fix deadlock on removal of regulators with supplies
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e032b376551a61662b20a2c8544fbbc568ab2e7f;p=linux-beck.git

regulator: Fix deadlock on removal of regulators with supplies

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@opensource.wolfsonmicro.com>
---

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index e2f3afa71efb..4a5054ef9421 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);