Re: [PATCH v6] hwmon: Add sht4x Temperature and Humidity Sensor Driver

From: kernel test robot
Date: Sat May 22 2021 - 16:12:41 EST


Hi Navin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on hwmon/hwmon-next]
[also build test WARNING on v5.13-rc2 next-20210521]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Navin-Sankar-Velliangiri/hwmon-Add-sht4x-Temperature-and-Humidity-Sensor-Driver/20210522-232201
base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
config: x86_64-randconfig-r033-20210523 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project e84a9b9bb3051c35dea993cdad7b3d2575638f85)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/a122a0f7b0de4be7208671bb4f68ee1e14a3f28e
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Navin-Sankar-Velliangiri/hwmon-Add-sht4x-Temperature-and-Humidity-Sensor-Driver/20210522-232201
git checkout a122a0f7b0de4be7208671bb4f68ee1e14a3f28e
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> drivers/hwmon/sht4x.c:84:2: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (!data->valid || time_after(jiffies, next_update)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:56:28: note: expanded from macro 'if'
#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hwmon/sht4x.c:125:9: note: uninitialized use occurs here
return ret;
^~~
drivers/hwmon/sht4x.c:84:2: note: remove the 'if' if its condition is always true
if (!data->valid || time_after(jiffies, next_update)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:56:23: note: expanded from macro 'if'
#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
^
drivers/hwmon/sht4x.c:74:9: note: initialize the variable 'ret' to silence this warning
int ret;
^
= 0
1 warning generated.


vim +84 drivers/hwmon/sht4x.c

66
67 /**
68 * sht4x_read_values() - read and parse the raw data from the SHT4X
69 * @sht4x_data: the struct sht4x_data to use for the lock
70 * Return: 0 if succesfull, 1 if not
71 */
72 static int sht4x_read_values(struct sht4x_data *data)
73 {
74 int ret;
75 u16 t_ticks, rh_ticks;
76 unsigned long next_update;
77 struct i2c_client *client = data->client;
78 u8 crc, raw_data[SHT4X_RESPONSE_LENGTH],
79 cmd[] = {SHT4X_CMD_MEASURE_HPM};
80
81 mutex_lock(&data->lock);
82 next_update = data->last_updated +
83 msecs_to_jiffies(data->update_interval);
> 84 if (!data->valid || time_after(jiffies, next_update)) {
85 ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN);
86 if (ret < 0)
87 goto unlock;
88
89 usleep_range(SHT4X_MEAS_DELAY,
90 SHT4X_MEAS_DELAY + SHT4X_DELAY_EXTRA);
91
92 ret = i2c_master_recv(client, raw_data, SHT4X_RESPONSE_LENGTH);
93 if (ret != SHT4X_RESPONSE_LENGTH) {
94 if (ret >= 0)
95 ret = -ENODATA;
96
97 goto unlock;
98 }
99
100 t_ticks = raw_data[0] << 8 | raw_data[1];
101 rh_ticks = raw_data[3] << 8 | raw_data[4];
102
103 crc = crc8(sht4x_crc8_table, &raw_data[0], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
104 if (crc != raw_data[2]) {
105 dev_err(&client->dev, "data integrity check failed\n");
106 ret = -EIO;
107 goto unlock;
108 }
109
110 crc = crc8(sht4x_crc8_table, &raw_data[3], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
111 if (crc != raw_data[5]) {
112 dev_err(&client->dev, "data integrity check failed\n");
113 ret = -EIO;
114 goto unlock;
115 }
116
117 data->temperature = ((21875 * (int32_t)t_ticks) >> 13) - 45000;
118 data->humidity = ((15625 * (int32_t)rh_ticks) >> 13) - 6000;
119 data->last_updated = jiffies;
120 data->valid = true;
121 }
122
123 unlock:
124 mutex_unlock(&data->lock);
125 return ret;
126 }
127

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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