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 <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Fixes: 716fec9d1965 ("[SUBMITTED] regulator: core: avoid unused variable warning") --- rebased on top of regulators.git #for-next diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c9bdca5f3b9b..89e4dcb84758 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); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
