| From 923bfd0cc424b4bc376a8be35ae44ce7ec535164 Mon Sep 17 00:00:00 2001 |
| From: Steve Twiss <stwiss.opensource@diasemi.com> |
| Date: Tue, 26 Feb 2019 15:32:18 +0000 |
| Subject: regulator: lp8755: Fix notifier mutex lock warning |
| |
| [ 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@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/lp8755.c | 15 ++++++++++++--- |
| 1 file changed, 12 insertions(+), 3 deletions(-) |
| |
| diff --git a/drivers/regulator/lp8755.c b/drivers/regulator/lp8755.c |
| index 14fd388071349..2e16a6ab491d6 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 regulator 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 regulator 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 |
| |