[ Upstream commit f132da2534ec6599c78c4adcef15340cff2e9dd9 ]
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: 3eb2c7ecb7ea ("regulator: Add LTC3589 support") Suggested-by: Adam Thomson Adam.Thomson.Opensource@diasemi.com Signed-off-by: Steve Twiss stwiss.opensource@diasemi.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/regulator/ltc3589.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/regulator/ltc3589.c b/drivers/regulator/ltc3589.c index 63f724f260ef7..75089b037b723 100644 --- a/drivers/regulator/ltc3589.c +++ b/drivers/regulator/ltc3589.c @@ -419,16 +419,22 @@ static irqreturn_t ltc3589_isr(int irq, void *dev_id)
if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) { event = REGULATOR_EVENT_OVER_TEMP; - for (i = 0; i < LTC3589_NUM_REGULATORS; i++) + for (i = 0; i < LTC3589_NUM_REGULATORS; i++) { + regulator_lock(ltc3589->regulators[i]); regulator_notifier_call_chain(ltc3589->regulators[i], event, NULL); + regulator_unlock(ltc3589->regulators[i]); + } }
if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) { event = REGULATOR_EVENT_UNDER_VOLTAGE; - for (i = 0; i < LTC3589_NUM_REGULATORS; i++) + for (i = 0; i < LTC3589_NUM_REGULATORS; i++) { + regulator_lock(ltc3589->regulators[i]); regulator_notifier_call_chain(ltc3589->regulators[i], event, NULL); + regulator_unlock(ltc3589->regulators[i]); + } }
/* Clear warning condition */