[ Upstream commit f7a621728a6a23bfd2c6ac4d3e42e1303aefde0f ]
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: d4d6b722e780 ("regulator: Add WM831x ISINK support") Suggested-by: Adam Thomson Adam.Thomson.Opensource@diasemi.com Signed-off-by: Steve Twiss stwiss.opensource@diasemi.com Acked-by: Charles Keepax ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/regulator/wm831x-isink.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/regulator/wm831x-isink.c b/drivers/regulator/wm831x-isink.c index 6dd891d7eee3b..11f351191dba9 100644 --- a/drivers/regulator/wm831x-isink.c +++ b/drivers/regulator/wm831x-isink.c @@ -140,9 +140,11 @@ static irqreturn_t wm831x_isink_irq(int irq, void *data) { struct wm831x_isink *isink = data;
+ regulator_lock(isink->regulator); regulator_notifier_call_chain(isink->regulator, REGULATOR_EVENT_OVER_CURRENT, NULL); + regulator_unlock(isink->regulator);
return IRQ_HANDLED; }