Hello Matthias Fetzer,
Commit 57d0557dfa49 ("platform/x86: thinkpad_acpi: Add Thinkpad Edge
E531 fan support") from Aug 16, 2024 (linux-next), leads to the
following Smatch static checker warning:
drivers/platform/x86/thinkpad_acpi.c:8387 fan_set_enable()
error: uninitialized symbol 's'.
drivers/platform/x86/thinkpad_acpi.c
8319 static int fan_set_enable(void)
8320 {
8321 u8 s;
8322 int rc;
8323
8324 if (!fan_control_allowed)
8325 return -EPERM;
8326
8327 if (mutex_lock_killable(&fan_mutex))
8328 return -ERESTARTSYS;
8329
8330 switch (fan_control_access_mode) {
8331 case TPACPI_FAN_WR_ACPI_FANS:
8332 case TPACPI_FAN_WR_TPEC:
8333 rc = fan_get_status(&s);
8334 if (rc)
8335 break;
8336
8337 /* Don't go out of emergency fan mode */
8338 if (s != 7) {
8339 s &= 0x07;
8340 s |= TP_EC_FAN_AUTO | 4; /* min fan speed 4 */
8341 }
8342
8343 if (!acpi_ec_write(fan_status_offset, s))
8344 rc = -EIO;
8345 else {
8346 tp_features.fan_ctrl_status_undef = 0;
8347 rc = 0;
8348 }
8349 break;
8350
8351 case TPACPI_FAN_WR_ACPI_SFAN:
8352 rc = fan_get_status(&s);
8353 if (rc)
8354 break;
8355
8356 s &= 0x07;
8357
8358 /* Set fan to at least level 4 */
8359 s |= 4;
8360
8361 if (!acpi_evalf(sfan_handle, NULL, NULL, "vd", s))
8362 rc = -EIO;
8363 else
8364 rc = 0;
8365 break;
8366
8367 case TPACPI_FAN_WR_ACPI_FANW:
8368 if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8106, 0x05)) {
8369 rc = -EIO;
8370 break;
8371 }
8372 if (!acpi_evalf(fanw_handle, NULL, NULL, "vdd", 0x8100, 0x00)) {
8373 rc = -EIO;
8374 break;
8375 }
8376
8377 rc = 0;
s isn't set on this path
8378 break;
8379
8380 default:
8381 rc = -ENXIO;
8382 }
8383
8384 mutex_unlock(&fan_mutex);
8385
8386 if (!rc)
--> 8387 vdbg_printk(TPACPI_DBG_FAN,
8388 "fan control: set fan control register to 0x%02x\n",
8389 s);
^
Here
8390 return rc;
8391 }
regards,
dan carpenter
