diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2015-11-27 16:46:41 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-11-27 19:37:04 +0300 |
| commit | bb41897e38c53458a88b271f2fbcd905ee1f9584 (patch) | |
| tree | 3f9cb105c24c182906db7fa0d6a287e5917a2f01 | |
| parent | fa731ac7ea04a7d3a5c6d2f568132478c02a83b3 (diff) | |
| download | linux-bb41897e38c53458a88b271f2fbcd905ee1f9584.tar.xz | |
regulator: core: fix regulator_lock_supply regression
As noticed by Geert Uytterhoeven, my patch to avoid a harmless build warning
in regulator_lock_supply() was total crap and introduced a real bug:
> [ BUG: bad unlock balance detected! ]
> kworker/u4:0/6 is trying to release lock (&rdev->mutex) at:
> [<c0247b84>] regulator_set_voltage+0x38/0x50
we still lock the regulator supplies, but not the actual regulators,
so we are missing a lock, and the unlock is unbalanced.
This rectifies it by first locking the regulator device itself before
using the same loop as before to lock its supplies.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 716fec9d1965 ("[SUBMITTED] regulator: core: avoid unused variable warning")
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | drivers/regulator/core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c70017d5f74b..daffff83ced2 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -140,7 +140,8 @@ static void regulator_lock_supply(struct regulator_dev *rdev) { int i; - for (i = 0; rdev->supply; rdev = rdev->supply->rdev, i++) + mutex_lock(&rdev->mutex); + for (i = 1; rdev->supply; rdev = rdev->supply->rdev, i++) mutex_lock_nested(&rdev->mutex, i); } |