The patch regulator: ltc3676: Fix notifier mutex lock warning
has been applied to the regulator tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 769fc8d4182c1d1875db7859852afeb436714c5c Mon Sep 17 00:00:00 2001 From: Steve Twiss <stwiss.opensou...@diasemi.com> Date: Tue, 26 Feb 2019 15:38:56 +0000 Subject: [PATCH] regulator: ltc3676: Fix notifier mutex lock warning 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.opensou...@diasemi.com> Signed-off-by: Steve Twiss <stwiss.opensou...@diasemi.com> Signed-off-by: Mark Brown <broo...@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 e6d66e492b85..4be90c78c720 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