[ Upstream commit 769fc8d4182c1d1875db7859852afeb436714c5c ]
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: 37b918a034fe ("regulator: Add LTC3676 support")
Suggested-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Signed-off-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/regulator/ltc3676.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/regulator/ltc3676.c b/drivers/regulator/ltc3676.c
index 71fd0f2a4b76e..cd0f11254c778 100644
--- a/drivers/regulator/ltc3676.c
+++ b/drivers/regulator/ltc3676.c
@@ -338,17 +338,23 @@ static irqreturn_t ltc3676_isr(int irq, void *dev_id)
if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) {
dev_warn(dev, "Over-temperature Warning\n");
event = REGULATOR_EVENT_OVER_TEMP;
- for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
+ for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
+ regulator_lock(ltc3676->regulators[i]);
regulator_notifier_call_chain(ltc3676->regulators[i],
event, NULL);
+ regulator_unlock(ltc3676->regulators[i]);
+ }
}
if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) {
dev_info(dev, "Undervoltage Warning\n");
event = REGULATOR_EVENT_UNDER_VOLTAGE;
- for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
+ for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
+ regulator_lock(ltc3676->regulators[i]);
regulator_notifier_call_chain(ltc3676->regulators[i],
event, NULL);
+ regulator_unlock(ltc3676->regulators[i]);
+ }
}
/* Clear warning condition */
--
2.20.1
