Re: [PATCH 2/7] drivers/hwmon: add local variable for newly allocated attribute_group**

From: Guenter Roeck <linux@roeck-us.net>
To: Max Kellermann <max.kellermann@ionos.com>
Cc: Jean Delvare <jdelvare@suse.com>,
	linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/7] drivers/hwmon: add local variable for newly allocated attribute_group**
Date: Mon, 9 Oct 2023 10:19:04 -0700	[thread overview]
Message-ID: <bab3c83c-2ba8-4d23-b3cb-2f233898f7f2@roeck-us.net> (raw)
In-Reply-To: <20231009165741.746184-2-max.kellermann@ionos.com>

On Mon, Oct 09, 2023 at 06:57:35PM +0200, Max Kellermann wrote:
> This allows the compiler to keep the pointer in a register and
> prepares for making the struct field "const".
> 
> Signed-off-by: Max Kellermann <max.kellermann@ionos.com>

I have no idea what this is about, and I don't see how that would
improve anything, but ...

> ---
>  drivers/hwmon/hwmon.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
> index c7dd3f5b2bd5..e50ab229b27d 100644
> --- a/drivers/hwmon/hwmon.c
> +++ b/drivers/hwmon/hwmon.c
> @@ -783,6 +783,7 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
>  	hdev = &hwdev->dev;
>  
>  	if (chip) {
> +		const struct attribute_group **new_groups;
>  		struct attribute **attrs;
>  		int ngroups = 2; /* terminating NULL plus &hwdev->groups */
>  
> @@ -790,8 +791,8 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
>  			for (i = 0; groups[i]; i++)
>  				ngroups++;
>  
> -		hwdev->groups = kcalloc(ngroups, sizeof(*groups), GFP_KERNEL);
> -		if (!hwdev->groups) {
> +		hwdev->groups = new_groups = kcalloc(ngroups, sizeof(*new_groups), GFP_KERNEL);

CHECK: multiple assignments should be avoided
#101: FILE: drivers/hwmon/hwmon.c:794:
+		hwdev->groups = new_groups = kcalloc(ngroups, sizeof(*new_groups), GFP_KERNEL);

either case, this change is not acceptable.

Guenter