On 7/31/24 10:42, Guenter Roeck wrote:
On 7/31/24 10:31, Dan Carpenter wrote:Hello Guenter Roeck, Commit ec408845bc0f ("hwmon: (nct7802) Use multi-byte regmap operations") from Jul 9, 2024 (linux-next), leads to the following Smatch static checker warning: drivers/hwmon/nct7802.c:411 in_alarm_show() error: double locked '&data->access_lock' (orig line 406) drivers/hwmon/nct7802.c 375 static ssize_t in_alarm_show(struct device *dev, struct device_attribute *attr, 376 char *buf) 377 { 378 struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr); 379 struct nct7802_data *data = dev_get_drvdata(dev); 380 int volt, min, max, ret; 381 unsigned int val; 382 383 mutex_lock(&data->in_alarm_lock); 384 385 /* 386 * The SMI Voltage status register is the only register giving a status 387 * for voltages. A bit is set for each input crossing a threshold, in 388 * both direction, but the "inside" or "outside" limits info is not 389 * available. Also this register is cleared on read. 390 * Note: this is not explicitly spelled out in the datasheet, but 391 * from experiment. 392 * To deal with this we use a status cache with one validity bit and 393 * one status bit for each input. Validity is cleared at startup and 394 * each time the register reports a change, and the status is processed 395 * by software based on current input value and limits. 396 */ 397 ret = regmap_read(data->regmap, 0x1e, &val); /* SMI Voltage status */ 398 if (ret < 0) 399 goto abort; 400 401 /* invalidate cached status for all inputs crossing a threshold */ 402 data->in_status &= ~((val & 0x0f) << 4); 403 404 /* if cached status for requested input is invalid, update it */ 405 if (!(data->in_status & (0x10 << sattr->index))) { 406 ret = nct7802_read_voltage(data, sattr->nr, 0); I believe that the mutex_lock(&data->access_lock); in nct7802_read_voltage() was supposed to be deleted.Oops, most definitely yes.
This is now fixed. Again, thanks a lot for the report. Guenter
