tree: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x8... review-hans head: 8d01cf643b3f8bc79c5b6bf18382b943143d9090 commit: 8074a79fad2e34fce11ea2b2c515b984fc6b2a08 [79/82] platform/x86: intel_pmc_core: Add option to set/clear LPM mode config: x86_64-randconfig-m001-20210419 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; smatch warnings: drivers/platform/x86/intel_pmc_core.c:1369 pmc_core_lpm_latch_mode_write() warn: unsigned 'ret' is never less than zero. vim +/ret +1369 drivers/platform/x86/intel_pmc_core.c 1352 1353 static ssize_t pmc_core_lpm_latch_mode_write(struct file *file, 1354 const char __user *userbuf, 1355 size_t count, loff_t *ppos) 1356 { 1357 struct seq_file *s = file->private_data; 1358 struct pmc_dev *pmcdev = s->private; 1359 bool clear = false, c10 = false; 1360 unsigned char buf[8]; 1361 size_t ret; 1362 int idx, m, mode; 1363 u32 reg; 1364 1365 if (count > sizeof(buf) - 1) 1366 return -EINVAL; 1367 1368 ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, userbuf, count); 1370 return ret; 1371 1372 buf[count] = '\0'; 1373 1374 /* 1375 * Allowed strings are: 1376 * Any enabled substate, e.g. 'S0i2.0' 1377 * 'c10' 1378 * 'clear' 1379 */ 1380 mode = sysfs_match_string(pmc_lpm_modes, buf); 1381 1382 /* Check string matches enabled mode */ 1383 pmc_for_each_mode(idx, m, pmcdev) 1384 if (mode == m) 1385 break; 1386 1387 if (mode != m || mode < 0) { 1388 if (sysfs_streq(buf, "clear")) 1389 clear = true; 1390 else if (sysfs_streq(buf, "c10")) 1391 c10 = true; 1392 else 1393 return -EINVAL; 1394 } 1395 1396 if (clear) { 1397 mutex_lock(&pmcdev->lock); 1398 1399 reg = pmc_core_reg_read(pmcdev, pmcdev->map->etr3_offset); 1400 reg |= ETR3_CLEAR_LPM_EVENTS; 1401 pmc_core_reg_write(pmcdev, pmcdev->map->etr3_offset, reg); 1402 1403 mutex_unlock(&pmcdev->lock); 1404 1405 return count; 1406 } 1407 1408 if (c10) { 1409 mutex_lock(&pmcdev->lock); 1410 1411 reg = pmc_core_reg_read(pmcdev, pmcdev->map->lpm_sts_latch_en_offset); 1412 reg &= ~LPM_STS_LATCH_MODE; 1413 pmc_core_reg_write(pmcdev, pmcdev->map->lpm_sts_latch_en_offset, reg); 1414 1415 mutex_unlock(&pmcdev->lock); 1416 1417 return count; 1418 } 1419 1420 /* 1421 * For LPM mode latching we set the latch enable bit and selected mode 1422 * and clear everything else. 1423 */ 1424 reg = LPM_STS_LATCH_MODE | BIT(mode); 1425 mutex_lock(&pmcdev->lock); 1426 pmc_core_reg_write(pmcdev, pmcdev->map->lpm_sts_latch_en_offset, reg); 1427 mutex_unlock(&pmcdev->lock); 1428 1429 return count; 1430 } 1431 DEFINE_PMC_CORE_ATTR_WRITE(pmc_core_lpm_latch_mode); 1432 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org