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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Guenter Roeck <linux@roeck-us.net>,
        Sasha Levin <sashal@kernel.org>, jdelvare@suse.com,
        corbet@lwn.net, linux-hwmon@vger.kernel.org,
        linux-doc@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 52/55] hwmon: Make chip parameter for with_info API mandatory
Date:   Mon, 30 May 2022 09:46:58 -0400
Message-Id: <20220530134701.1935933-52-sashal@kernel.org>
In-Reply-To: <20220530134701.1935933-1-sashal@kernel.org>
References: <20220530134701.1935933-1-sashal@kernel.org>
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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.rst |  2 +-
 drivers/hwmon/hwmon.c                    | 16 +++++++---------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/Documentation/hwmon/hwmon-kernel-api.rst b/Documentation/hwmon/hwmon-kernel-api.rst
index c41eb6108103..23f27fe78e37 100644
--- a/Documentation/hwmon/hwmon-kernel-api.rst
+++ b/Documentation/hwmon/hwmon-kernel-api.rst
@@ -72,7 +72,7 @@ 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 a2175394cd25..c73b93b9bb87 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -715,11 +715,12 @@ 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.
@@ -732,13 +733,10 @@ 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