diff options
| author | Thierry Reding <treding@nvidia.com> | 2015-12-02 18:54:50 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-12-02 20:22:10 +0300 |
| commit | 70a7fb80e85ae7f78f8e90cec3fbd862ea6a4d4b (patch) | |
| tree | 4142e78c55ab9dec86d03d6820cda69ffd04a647 /drivers/regulator/core.c | |
| parent | 49a6bb7a1c0963f260e4b0dcc2c0e56ec65a28b2 (diff) | |
| download | linux-70a7fb80e85ae7f78f8e90cec3fbd862ea6a4d4b.tar.xz | |
regulator: core: Fix nested locking of supplies
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: Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/regulator/core.c')
| -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); } |