hwmon: (nct7904) Read all SMI status registers in probe function

When nct7904 power up, it compares current sensor readings against the
default threshold immediately. This results in false alarms on startup.
Read all SMI status registers in probe function to clear the alarms.

Signed-off-by: Amy Shih <amy.shih@advantech.com.tw>
[groeck: Reworded description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c
index 1f5743d68984cfb93ef9ea25084f3db6e1fcbf8a..8d59cff377557b4fa4801c33a4c8eccbe435473b 100644 (file)
--- a/drivers/hwmon/nct7904.c
+++ b/drivers/hwmon/nct7904.c
@@ -41,6 +41,7 @@
 #define FANCTL_MAX             4       /* Counted from 1 */
 #define TCPU_MAX               8       /* Counted from 1 */
 #define TEMP_MAX               4       /* Counted from 1 */
+#define SMI_STS_MAX            10      /* Counted from 1 */
 
 #define VT_ADC_CTRL0_REG       0x20    /* Bank 0 */
 #define VT_ADC_CTRL1_REG       0x21    /* Bank 0 */
@@ -1009,6 +1010,13 @@ static int nct7904_probe(struct i2c_client *client,
                data->fan_mode[i] = ret;
        }
 
+       /* Read all of SMI status register to clear alarms */
+       for (i = 0; i < SMI_STS_MAX; i++) {
+               ret = nct7904_read_reg(data, BANK_0, SMI_STS1_REG + i);
+               if (ret < 0)
+                       return ret;
+       }
+
        hwmon_dev =
                devm_hwmon_device_register_with_info(dev, client->name, data,
                                                     &nct7904_chip_info, NULL);