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| author | Thierry Reding <treding@nvidia.com> | 2015-12-02 16:54:50 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-04 14:48:50 -0700 |
| commit | 5a58f809d731c23c0b898d2021903db8dee4466f (patch) | |
| tree | 289f098a27c6187d12fa7e38fb93b992a520a4d2 /drivers/regulator | |
| parent | 29c9f634cb132107df3e4f07c8e48b35d04b527b (diff) | |
| download | linux-stable-5a58f809d731c23c0b898d2021903db8dee4466f.tar.gz linux-stable-5a58f809d731c23c0b898d2021903db8dee4466f.tar.bz2 linux-stable-5a58f809d731c23c0b898d2021903db8dee4466f.zip | |
regulator: core: Fix nested locking of supplies
commit 70a7fb80e85ae7f78f8e90cec3fbd862ea6a4d4b upstream.
Commit fa731ac7ea04 ("regulator: core: avoid unused variable warning")
introduced a subtle change in how supplies are locked. Where previously
code was always locking the regulator of the current iteration, the new
implementation only locks the regulator if it has a supply. For any
given power tree that means that the root will never get locked.
On the other hand the regulator_unlock_supply() will still release all
the locks, which in turn causes the lock debugging code to warn about a
mutex being unlocked which wasn't locked.
Cc: Mark Brown <broonie@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/regulator')
| -rw-r--r-- | drivers/regulator/core.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index f71db02fcb71..732ac71b82cd 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -132,6 +132,14 @@ static bool have_full_constraints(void) return has_full_constraints || of_have_populated_dt(); } +static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev) +{ + if (rdev && rdev->supply) + return rdev->supply->rdev; + + return NULL; +} + /** * regulator_lock_supply - lock a regulator and its supplies * @rdev: regulator source @@ -140,8 +148,7 @@ static void regulator_lock_supply(struct regulator_dev *rdev) { int i; - mutex_lock(&rdev->mutex); - for (i = 1; rdev; rdev = rdev->supply->rdev, i++) + for (i = 0; rdev; rdev = rdev_get_supply(rdev), i++) mutex_lock_nested(&rdev->mutex, i); } |