[ Upstream commit 89b2758c192c35068b07766a6830433bfbdc1f44 ]
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: b59320cc5a5e ("regulator: lp8755: new driver for LP8755")
Suggested-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Signed-off-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/regulator/lp8755.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/regulator/lp8755.c b/drivers/regulator/lp8755.c
index 244822bb63cd6..d82d3077f3b82 100644
--- a/drivers/regulator/lp8755.c
+++ b/drivers/regulator/lp8755.c
@@ -372,10 +372,13 @@ static irqreturn_t lp8755_irq_handler(int irq, void *data)
for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
if ((flag0 & (0x4 << icnt))
&& (pchip->irqmask & (0x04 << icnt))
- && (pchip->rdev[icnt] != NULL))
+ && (pchip->rdev[icnt] != NULL)) {
+ regulator_lock(pchip->rdev[icnt]);
regulator_notifier_call_chain(pchip->rdev[icnt],
LP8755_EVENT_PWR_FAULT,
NULL);
+ regulator_unlock(pchip->rdev[icnt]);
+ }
/* read flag1 register */
ret = lp8755_read(pchip, 0x0E, &flag1);
@@ -389,18 +392,24 @@ static irqreturn_t lp8755_irq_handler(int irq, void *data)
/* send OCP event to all regualtor devices */
if ((flag1 & 0x01) && (pchip->irqmask & 0x01))
for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
- if (pchip->rdev[icnt] != NULL)
+ if (pchip->rdev[icnt] != NULL) {
+ regulator_lock(pchip->rdev[icnt]);
regulator_notifier_call_chain(pchip->rdev[icnt],
LP8755_EVENT_OCP,
NULL);
+ regulator_unlock(pchip->rdev[icnt]);
+ }
/* send OVP event to all regualtor devices */
if ((flag1 & 0x02) && (pchip->irqmask & 0x02))
for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
- if (pchip->rdev[icnt] != NULL)
+ if (pchip->rdev[icnt] != NULL) {
+ regulator_lock(pchip->rdev[icnt]);
regulator_notifier_call_chain(pchip->rdev[icnt],
LP8755_EVENT_OVP,
NULL);
+ regulator_unlock(pchip->rdev[icnt]);
+ }
return IRQ_HANDLED;
err_i2c:
--
2.20.1
