[PATCH] regulator: da9055: Fix notifier mutex lock warning

From: Steve Twiss
Date: Tue Feb 26 2019 - 09:59:59 EST

The mutex for the regulator_dev must be controlled by the caller of
the regulator_notifier_call_chain(), as described in the comment
for that function.

Failure to mutex lock and unlock surrounding the notifier call results
in a kernel WARN_ON_ONCE() which will dump a backtrace for the
regulator_notifier_call_chain() when that function call is first made.
The mutex can be controlled using the regulator_lock/unlock() API.

Fixes: f6130be652d0 ("regulator: DA9055 regulator driver")
Suggested-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Signed-off-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
drivers/regulator/da9055-regulator.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/regulator/da9055-regulator.c b/drivers/regulator/da9055-regulator.c
index 3c6fac793658..3ade4b8d204e 100644
--- a/drivers/regulator/da9055-regulator.c
+++ b/drivers/regulator/da9055-regulator.c
@@ -487,8 +487,10 @@ static irqreturn_t da9055_ldo5_6_oc_irq(int irq, void *data)
struct da9055_regulator *regulator = data;

+ regulator_lock(regulator->rdev);
+ regulator_unlock(regulator->rdev);