diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2015-11-27 14:46:41 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-04 14:48:50 -0700 |
| commit | f500da32a1663c1bb2587ff04be08d5220b3afca (patch) | |
| tree | 3e8715902654b292f9ff86b7601237725bc88f01 /drivers | |
| parent | 34af67eb941ae5371110c9adbd5392c7a3aa841e (diff) | |
regulator: core: fix regulator_lock_supply regression
commit bb41897e38c53458a88b271f2fbcd905ee1f9584 upstream.
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>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -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); } |