regulator: da9062: Fix notifier mutex lock warning

BugLink: https://bugs.launchpad.net/bugs/1837517
[ Upstream commit 978995def0f6030aa6b3b494682f673aca13881b ]

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: 4068e5182ada ("regulator: da9062: DA9062 regulator driver")
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>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/regulator/da9062-regulator.c b/drivers/regulator/da9062-regulator.c
index 34a70d9dc450e118f86b1e1ca8fcd954632775c0..5224304c10b3f96f9b79340bb3fe9a0672c26497 100644 (file)
--- a/drivers/regulator/da9062-regulator.c
+++ b/drivers/regulator/da9062-regulator.c
@@ -974,8 +974,10 @@ static irqreturn_t da9062_ldo_lim_event(int irq, void *data)
                        continue;
 
                if (BIT(regl->info->oc_event.lsb) & bits) {
+                       regulator_lock(regl->rdev);
                        regulator_notifier_call_chain(regl->rdev,
                                        REGULATOR_EVENT_OVER_CURRENT, NULL);
+                       regulator_unlock(regl->rdev);
                        handled = IRQ_HANDLED;
                }
        }