[ Upstream commit 1867af94cfdf37fc70fe67b3d522e78352800196 ]
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: 99cf3af5e2d5 ("regulator: pv88080: new regulator driver") 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/pv88080-regulator.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/regulator/pv88080-regulator.c b/drivers/regulator/pv88080-regulator.c index 9a08cb2de501e..d99f1b9fa0756 100644 --- a/drivers/regulator/pv88080-regulator.c +++ b/drivers/regulator/pv88080-regulator.c @@ -384,9 +384,11 @@ static irqreturn_t pv88080_irq_handler(int irq, void *data) if (reg_val & PV88080_E_VDD_FLT) { for (i = 0; i < PV88080_MAX_REGULATORS; i++) { if (chip->rdev[i] != NULL) { + regulator_lock(chip->rdev[i]); regulator_notifier_call_chain(chip->rdev[i], REGULATOR_EVENT_UNDER_VOLTAGE, NULL); + regulator_unlock(chip->rdev[i]); } }
@@ -401,9 +403,11 @@ static irqreturn_t pv88080_irq_handler(int irq, void *data) if (reg_val & PV88080_E_OVER_TEMP) { for (i = 0; i < PV88080_MAX_REGULATORS; i++) { if (chip->rdev[i] != NULL) { + regulator_lock(chip->rdev[i]); regulator_notifier_call_chain(chip->rdev[i], REGULATOR_EVENT_OVER_TEMP, NULL); + regulator_unlock(chip->rdev[i]); } }