Hi, Thank you for the patch! Yet something to improve: [auto build test ERROR on abelloni/rtc-next] [also build test ERROR 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/qxj511mail-gmail-com/rtc-rs5c372... base: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next config: x86_64-randconfig-s031-20210522 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-341-g8af24329-dirty # https://github.com/0day-ci/linux/commit/62c495535e38dc184558713e6c007071f... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review qxj511mail-gmail-com/rtc-rs5c372-Fix-read-the-time-from-RTC-is-illegal-When-reading-time-from-an-uninitialized-RTC-chip-The-value-may-be-ille/20210522-202320 git checkout 62c495535e38dc184558713e6c007071f50f516c # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/rtc/rtc-rs5c372.c: In function 'rs5c372_rtc_read_time': 261 | rs5c372_rtc_set_time(dev, tm); | ^~~~~~~~~~~~~~~~~~~~ | rs5c372_rtc_read_time drivers/rtc/rtc-rs5c372.c: At top level: 273 | static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm) | ^~~~~~~~~~~~~~~~~~~~ drivers/rtc/rtc-rs5c372.c:261:3: note: previous implicit declaration of 'rs5c372_rtc_set_time' was here 261 | rs5c372_rtc_set_time(dev, tm); | ^~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +261 drivers/rtc/rtc-rs5c372.c 208 209 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm) 210 { 211 struct i2c_client *client = to_i2c_client(dev); 212 struct rs5c372 *rs5c = i2c_get_clientdata(client); 213 int status = rs5c_get_regs(rs5c); 214 unsigned char ctrl2 = rs5c->regs[RS5C_REG_CTRL2]; 215 int flags_utime = 0; 216 217 if (status < 0) 218 return status; 219 220 switch (rs5c->type) { 221 case rtc_r2025sd: 222 case rtc_r2221tl: 223 if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) || 224 (rs5c->type == rtc_r2221tl && (ctrl2 & R2x2x_CTRL2_XSTP))) { 225 dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n"); 226 return -EINVAL; 227 } 228 break; 229 default: 230 if (ctrl2 & RS5C_CTRL2_XSTP) { 231 dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n"); 232 return -EINVAL; 233 } 234 } 235 236 tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f); 237 tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f); 238 tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]); 239 240 tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07); 241 tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f); 242 243 if (tm->tm_mday < 1) { 244 // The value read from the register may be zero, which is an illegal value 245 flags_utime = flags_utime + 1; 246 tm->tm_mday = 1; 247 } 248 249 /* tm->tm_mon is zero-based */ 250 tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1; 251 252 if (tm->tm_mon < 0) { 253 flags_utime = flags_utime + 1; 254 tm->tm_mon = 0; 255 } 256 257 /* year is 1900 + tm->tm_year */ 258 tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100; 259 260 if (flags_utime > 0) { 262 } 263 264 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " 265 "mday=%d, mon=%d, year=%d, wday=%d\n", 266 __func__, 267 tm->tm_sec, tm->tm_min, tm->tm_hour, 268 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 269 270 return 0; 271 } 272 274 { 275 struct i2c_client *client = to_i2c_client(dev); 276 struct rs5c372 *rs5c = i2c_get_clientdata(client); 277 unsigned char buf[7]; 278 unsigned char ctrl2; 279 int addr; 280 281 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d " 282 "mday=%d, mon=%d, year=%d, wday=%d\n", 283 __func__, 284 tm->tm_sec, tm->tm_min, tm->tm_hour, 285 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 286 287 addr = RS5C_ADDR(RS5C372_REG_SECS); 288 buf[0] = bin2bcd(tm->tm_sec); 289 buf[1] = bin2bcd(tm->tm_min); 290 buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour); 291 buf[3] = bin2bcd(tm->tm_wday); 292 buf[4] = bin2bcd(tm->tm_mday); 293 buf[5] = bin2bcd(tm->tm_mon + 1); 294 buf[6] = bin2bcd(tm->tm_year - 100); 295 296 if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) { 297 dev_dbg(&client->dev, "%s: write error in line %i\n", 298 __func__, __LINE__); 299 return -EIO; 300 } 301 302 addr = RS5C_ADDR(RS5C_REG_CTRL2); 303 ctrl2 = i2c_smbus_read_byte_data(client, addr); 304 305 /* clear rtc warning bits */ 306 switch (rs5c->type) { 307 case rtc_r2025sd: 308 case rtc_r2221tl: 309 ctrl2 &= ~(R2x2x_CTRL2_VDET | R2x2x_CTRL2_PON); 310 if (rs5c->type == rtc_r2025sd) 311 ctrl2 |= R2x2x_CTRL2_XSTP; 312 else 313 ctrl2 &= ~R2x2x_CTRL2_XSTP; 314 break; 315 default: 316 ctrl2 &= ~RS5C_CTRL2_XSTP; 317 break; 318 } 319 320 if (i2c_smbus_write_byte_data(client, addr, ctrl2) < 0) { 321 dev_dbg(&client->dev, "%s: write error in line %i\n", 322 __func__, __LINE__); 323 return -EIO; 324 } 325 326 return 0; 327 } 328 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org