hwmon: (core) check parent dev != NULL when chip != NULL

hwmon_device_register_with_info() registration API requires a
non-NULL parent device when chip is non-NULL.

This commit adds a check and documents this requirement.

Signed-off-by: Lucas Magasweran <lucas.magasweran@ieee.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
index 53a806696c64923be8fdeb97fb6b474a696f83d2..eb7a78aebb3801f43463d92d990d1efbf8e642e4 100644 (file)
--- a/Documentation/hwmon/hwmon-kernel-api.txt
+++ b/Documentation/hwmon/hwmon-kernel-api.txt
@@ -71,7 +71,8 @@ hwmon_device_register_with_info is the most comprehensive and preferred means
 to register a hardware monitoring device. It creates the standard sysfs
 attributes in the hardware monitoring core, letting the driver focus on reading
 from and writing to the chip instead of having to bother with sysfs attributes.
-Its parameters are described in more detail below.
+The parent device parameter cannot be NULL with non-NULL chip info. Its
+parameters are described in more detail below.
 
 devm_hwmon_device_register_with_info is similar to
 hwmon_device_register_with_info. However, it is device managed, meaning the

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 32083e452cded72c2cd4554691ffa7dd316685d3..e88c019619481d16ab7690ecc8a862f94733e309 100644 (file)
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -698,6 +698,9 @@ hwmon_device_register_with_info(struct device *dev, const char *name,
        if (chip && (!chip->ops || !chip->ops->is_visible || !chip->info))
                return ERR_PTR(-EINVAL);
 
+       if (chip && !dev)
+               return ERR_PTR(-EINVAL);
+
        return __hwmon_device_register(dev, name, drvdata, chip, extra_groups);
 }
 EXPORT_SYMBOL_GPL(hwmon_device_register_with_info);