Re: [PATCH] hwmon: (pmbus/acbel-fsg032) Add firmware version debugfs attribute

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 6/28/23 23:53, Dan Carpenter wrote:
> Hi Eddie,
>
> kernel test robot noticed the following build warnings:
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Eddie-James/hwmon-pmbus-acbel-fsg032-Add-firmware-version-debugfs-attribute/20230628-030615
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
> patch link:    https://lore.kernel.org/r/20230627184027.16343-1-eajames%40linux.ibm.com
> patch subject: [PATCH] hwmon: (pmbus/acbel-fsg032) Add firmware version debugfs attribute
> config: x86_64-randconfig-m001-20230627 (https://download.01.org/0day-ci/archive/20230628/202306281205.NFXmu7xb-lkp@xxxxxxxxx/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20230628/202306281205.NFXmu7xb-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> | Closes: https://lore.kernel.org/r/202306281205.NFXmu7xb-lkp@xxxxxxxxx/
>
> smatch warnings:
> drivers/hwmon/pmbus/acbel-fsg032.c:36 acbel_fsg032_debugfs_read() warn: argument 4 to %02X specifier has type 'char'
>
> vim +/char +36 drivers/hwmon/pmbus/acbel-fsg032.c
>
> d2c6444389b625 Eddie James 2023-06-27  17  static ssize_t acbel_fsg032_debugfs_read(struct file *file, char __user *buf, size_t count,
> d2c6444389b625 Eddie James 2023-06-27  18  					 loff_t *ppos)
> d2c6444389b625 Eddie James 2023-06-27  19  {
> d2c6444389b625 Eddie James 2023-06-27  20  	struct i2c_client *client = file->private_data;
> d2c6444389b625 Eddie James 2023-06-27  21  	char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
>
> data should probably be a u8.
>
> d2c6444389b625 Eddie James 2023-06-27  22  	char out[8];
> d2c6444389b625 Eddie James 2023-06-27  23  	int rc;
> d2c6444389b625 Eddie James 2023-06-27  24  	int i;
> d2c6444389b625 Eddie James 2023-06-27  25
> d2c6444389b625 Eddie James 2023-06-27  26  	rc = pmbus_lock_interruptible(client);
> d2c6444389b625 Eddie James 2023-06-27  27  	if (rc)
> d2c6444389b625 Eddie James 2023-06-27  28  		return rc;
> d2c6444389b625 Eddie James 2023-06-27  29
> d2c6444389b625 Eddie James 2023-06-27  30  	rc = i2c_smbus_read_block_data(client, ACBEL_MFR_FW_REVISION, data);
> d2c6444389b625 Eddie James 2023-06-27  31  	pmbus_unlock(client);
> d2c6444389b625 Eddie James 2023-06-27  32  	if (rc < 0)
> d2c6444389b625 Eddie James 2023-06-27  33  		return rc;
> d2c6444389b625 Eddie James 2023-06-27  34
> d2c6444389b625 Eddie James 2023-06-27  35  	for (i = 0; i < rc && i < 3; ++i)
> d2c6444389b625 Eddie James 2023-06-27 @36  		snprintf(&out[i * 2], 3, "%02X", data[i]);
>
> If data[i] is negative this will print FFFFFFF1 etc.  (This is an x86
> config...  Did we ever merge that patch to make char signed by default?)

That makes me wonder what "%*phN\n" in the updated patch does, as it only passes
'data' as pointer argument.

Either case, no need to resend. I fixed this up when applying it by
declaring data[] as u8. I also dropped the unused variable.

Thanks,
Guenter