hwmon: (pmbus_core) Fix Deadlock in pmbus_regulator_get_status

pmbus_regulator_get_status() acquires update_lock.
pmbus_regulator_get_error_flags() acquires it again, resulting in an
immediate deadlock.

Call _pmbus_get_flags() from pmbus_regulator_get_status() directly
to avoid the problem.

Reported-by: Patrick Rudolph <[email protected]>
Closes: https://lore.kernel.org/linux-hwmon/[email protected]/T/#u
Cc: Naresh Solanki <[email protected]>
Cc: [email protected] # v6.2+
Fixes: c05f477 ("hwmon: (pmbus/core) Implement regulator get_status")
Signed-off-by: Guenter Roeck <[email protected]>

Author: groeck

drivers/hwmon/pmbus/pmbus_core.c

@@ -2946,6 +2946,7 @@ static int pmbus_regulator_get_status(struct regulator_dev *rdev)
 	struct pmbus_data *data = i2c_get_clientdata(client);
 	u8 page = rdev_get_id(rdev);
 	int status, ret;
+	int event;
 
 	mutex_lock(&data->update_lock);
 	status = pmbus_get_status(client, page, PMBUS_STATUS_WORD);
@@ -2965,7 +2966,7 @@ static int pmbus_regulator_get_status(struct regulator_dev *rdev)
 		goto unlock;
 	}
 
-	ret = pmbus_regulator_get_error_flags(rdev, &status);
+	ret = _pmbus_get_flags(data, rdev_get_id(rdev), &status, &event, false);
 	if (ret)
 		goto unlock;