[PATCH AUTOSEL 4.19 36/38] hwmon: Make chip parameter for with_info API mandatory

[PATCH AUTOSEL 4.19 36/38] hwmon: Make chip parameter for with_info API mandatory

[Sasha Levin]

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit ddaefa209c4ac791c1262e97c9b2d0440c8ef1d5 ]

Various attempts were made recently to "convert" the old
hwmon_device_register() API to devm_hwmon_device_register_with_info()
by just changing the function name without actually converting the
driver. Prevent this from happening by making the 'chip' parameter of
devm_hwmon_device_register_with_info() mandatory.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 Documentation/hwmon/hwmon-kernel-api.txt |  2 +-
 drivers/hwmon/hwmon.c                    | 16 +++++++---------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
index eb7a78aebb38..4981df157b04 100644
--- a/Documentation/hwmon/hwmon-kernel-api.txt
+++ b/Documentation/hwmon/hwmon-kernel-api.txt
@@ -71,7 +71,7 @@ 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.
-The parent device parameter cannot be NULL with non-NULL chip info. Its
+The parent device parameter as well as the chip parameter must not be NULL. Its
 parameters are described in more detail below.
 
 devm_hwmon_device_register_with_info is similar to
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index c4051a3e63c2..fb82d8ee0dd6 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -695,11 +695,12 @@ EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);
 
 /**
  * hwmon_device_register_with_info - register w/ hwmon
- * @dev: the parent device
- * @name: hwmon name attribute
- * @drvdata: driver data to attach to created device
- * @chip: pointer to hwmon chip information
+ * @dev: the parent device (mandatory)
+ * @name: hwmon name attribute (mandatory)
+ * @drvdata: driver data to attach to created device (optional)
+ * @chip: pointer to hwmon chip information (mandatory)
  * @extra_groups: pointer to list of additional non-standard attribute groups
+ *	(optional)
  *
  * hwmon_device_unregister() must be called when the device is no
  * longer needed.
@@ -712,13 +713,10 @@ hwmon_device_register_with_info(struct device *dev, const char *name,
 				const struct hwmon_chip_info *chip,
 				const struct attribute_group **extra_groups)
 {
-	if (!name)
-		return ERR_PTR(-EINVAL);
-
-	if (chip && (!chip->ops || !chip->ops->is_visible || !chip->info))
+	if (!dev || !name || !chip)
 		return ERR_PTR(-EINVAL);
 
-	if (chip && !dev)
+	if (!chip->ops || !chip->ops->is_visible || !chip->info)
 		return ERR_PTR(-EINVAL);
 
 	return __hwmon_device_register(dev, name, drvdata, chip, extra_groups);
-- 
2.35.1

Re: [PATCH AUTOSEL 4.19 36/38] hwmon: Make chip parameter for with_info API mandatory

[Guenter Roeck]

On 5/30/22 06:49, Sasha Levin wrote:
> From: Guenter Roeck <linux@roeck-us.net>
> 
> [ Upstream commit ddaefa209c4ac791c1262e97c9b2d0440c8ef1d5 ]
> 
> Various attempts were made recently to "convert" the old
> hwmon_device_register() API to devm_hwmon_device_register_with_info()
> by just changing the function name without actually converting the
> driver. Prevent this from happening by making the 'chip' parameter of
> devm_hwmon_device_register_with_info() mandatory.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Sasha Levin <sashal@kernel.org>

Please drop.

Guenter

> ---
>   Documentation/hwmon/hwmon-kernel-api.txt |  2 +-
>   drivers/hwmon/hwmon.c                    | 16 +++++++---------
>   2 files changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
> index eb7a78aebb38..4981df157b04 100644
> --- a/Documentation/hwmon/hwmon-kernel-api.txt
> +++ b/Documentation/hwmon/hwmon-kernel-api.txt
> @@ -71,7 +71,7 @@ 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.
> -The parent device parameter cannot be NULL with non-NULL chip info. Its
> +The parent device parameter as well as the chip parameter must not be NULL. Its
>   parameters are described in more detail below.
>   
>   devm_hwmon_device_register_with_info is similar to
> diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
> index c4051a3e63c2..fb82d8ee0dd6 100644
> --- a/drivers/hwmon/hwmon.c
> +++ b/drivers/hwmon/hwmon.c
> @@ -695,11 +695,12 @@ EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);
>   
>   /**
>    * hwmon_device_register_with_info - register w/ hwmon
> - * @dev: the parent device
> - * @name: hwmon name attribute
> - * @drvdata: driver data to attach to created device
> - * @chip: pointer to hwmon chip information
> + * @dev: the parent device (mandatory)
> + * @name: hwmon name attribute (mandatory)
> + * @drvdata: driver data to attach to created device (optional)
> + * @chip: pointer to hwmon chip information (mandatory)
>    * @extra_groups: pointer to list of additional non-standard attribute groups
> + *	(optional)
>    *
>    * hwmon_device_unregister() must be called when the device is no
>    * longer needed.
> @@ -712,13 +713,10 @@ hwmon_device_register_with_info(struct device *dev, const char *name,
>   				const struct hwmon_chip_info *chip,
>   				const struct attribute_group **extra_groups)
>   {
> -	if (!name)
> -		return ERR_PTR(-EINVAL);
> -
> -	if (chip && (!chip->ops || !chip->ops->is_visible || !chip->info))
> +	if (!dev || !name || !chip)
>   		return ERR_PTR(-EINVAL);
>   
> -	if (chip && !dev)
> +	if (!chip->ops || !chip->ops->is_visible || !chip->info)
>   		return ERR_PTR(-EINVAL);
>   
>   	return __hwmon_device_register(dev, name, drvdata, chip, extra_groups);