Messages in this thread Patch in this message | | | From | Steve Twiss <> | Date | Tue, 26 Feb 2019 15:38:56 +0000 | Subject | [PATCH 07/13] regulator: ltc3676: Fix notifier mutex lock warning |
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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> --- 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 71fd0f2..cd0f112 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 */ -- 1.9.3
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