| From 2ee997b96ad2f721e0db2e40b01dfb7355f0c7a2 Mon Sep 17 00:00:00 2001 |
| From: Steve Twiss <stwiss.opensource@diasemi.com> |
| Date: Tue, 26 Feb 2019 15:38:56 +0000 |
| Subject: regulator: ltc3676: Fix notifier mutex lock warning |
| |
| [ 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@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/ltc3676.c | 10 ++++++++-- |
| 1 file changed, 8 insertions(+), 2 deletions(-) |
| |
| diff --git a/drivers/regulator/ltc3676.c b/drivers/regulator/ltc3676.c |
| index e6d66e492b851..4be90c78c7209 100644 |
| --- a/drivers/regulator/ltc3676.c |
| +++ b/drivers/regulator/ltc3676.c |
| @@ -285,17 +285,23 @@ 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 |
| |