regulator: da9063: Fix notifier mutex lock warning

BugLink: https://bugs.launchpad.net/bugs/1837517
[ Upstream commit 29d40b4a5776ec4727c9f0e00a884423dd5e3366 ]

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: 69ca3e58d178 ("regulator: da9063: Add Dialog DA9063 voltage regulators support.")
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/da9063-regulator.c b/drivers/regulator/da9063-regulator.c
index 8cbcd2a3eb2055d46da795f39b53c641a216ed6a..d3ea73ab59209e6b643b4a678ab319f560d859b6 100644 (file)
--- a/drivers/regulator/da9063-regulator.c
+++ b/drivers/regulator/da9063-regulator.c
@@ -615,9 +615,12 @@ static irqreturn_t da9063_ldo_lim_event(int irq, void *data)
                if (regl->info->oc_event.reg != DA9063_REG_STATUS_D)
                        continue;
 
-               if (BIT(regl->info->oc_event.lsb) & bits)
+               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);
+               }
        }
 
        return IRQ_HANDLED;