[ Upstream commit 8be64b6d87bd47d81753b60ddafe70102ebfd76b ]
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: d1c6b4fe668b ("regulator: Add WM831x LDO support")
Suggested-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Signed-off-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>
Acked-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/regulator/wm831x-ldo.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/regulator/wm831x-ldo.c b/drivers/regulator/wm831x-ldo.c
index e4a6f888484ec..fcd038e7cd803 100644
--- a/drivers/regulator/wm831x-ldo.c
+++ b/drivers/regulator/wm831x-ldo.c
@@ -51,9 +51,11 @@ static irqreturn_t wm831x_ldo_uv_irq(int irq, void *data)
{
struct wm831x_ldo *ldo = data;
+ regulator_lock(ldo->regulator);
regulator_notifier_call_chain(ldo->regulator,
REGULATOR_EVENT_UNDER_VOLTAGE,
NULL);
+ regulator_unlock(ldo->regulator);
return IRQ_HANDLED;
}
--
2.20.1
