diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
index 9f12aac4fab5..f4749c44cfb8 100644
--- a/Documentation/hwmon/max31790.rst
+++ b/Documentation/hwmon/max31790.rst
@@ -38,7 +38,7 @@ Sysfs entries
 fan[1-12]_input    RO  fan tachometer speed in RPM
 fan[1-12]_fault    RO  fan experienced fault
 fan[1-6]_target    RW  desired fan speed in RPM
-pwm[1-6]_enable    RW  regulator mode, 0=disabled, 1=manual mode, 2=rpm mode
+pwm[1-6]_enable    RW  regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode
 pwm[1-6]           RW  read: current pwm duty cycle,
                        write: target pwm duty cycle (0-255)
 ================== === =======================================================
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 344be7829d58..21b6b63b1c07 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -27,6 +27,7 @@
 
 /* Fan Config register bits */
 #define MAX31790_FAN_CFG_RPM_MODE	0x80
+#define MAX31790_FAN_CFG_CTRL_MON	0x10
 #define MAX31790_FAN_CFG_TACH_INPUT_EN	0x08
 #define MAX31790_FAN_CFG_TACH_INPUT	0x01
 
@@ -271,12 +272,12 @@ static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
 		*val = data->pwm[channel] >> 8;
 		return 0;
 	case hwmon_pwm_enable:
-		if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
-			*val = 2;
-		else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN)
-			*val = 1;
-		else
+		if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
 			*val = 0;
+		else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
+			*val = 2;
+		else
+			*val = 1;
 		return 0;
 	default:
 		return -EOPNOTSUPP;
@@ -307,23 +308,33 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
 	case hwmon_pwm_enable:
 		fan_config = data->fan_config[channel];
 		if (val == 0) {
-			fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
-					MAX31790_FAN_CFG_RPM_MODE);
+			fan_config |= MAX31790_FAN_CFG_CTRL_MON;
+			/*
+			 * Disable RPM mode; otherwise disabling fan speed
+			 * monitoring is not possible.
+			 */
+			fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
 		} else if (val == 1) {
-			fan_config = (fan_config |
-				      MAX31790_FAN_CFG_TACH_INPUT_EN) &
-				     ~MAX31790_FAN_CFG_RPM_MODE;
+			fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
 		} else if (val == 2) {
-			fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
-				      MAX31790_FAN_CFG_RPM_MODE;
+			fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
+			/*
+			 * The chip sets MAX31790_FAN_CFG_TACH_INPUT_EN on its
+			 * own if MAX31790_FAN_CFG_RPM_MODE is set.
+			 * Do it here as well to reflect the actual register
+			 * value in the cache.
+			 */
+			fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
 		} else {
 			err = -EINVAL;
 			break;
 		}
-		data->fan_config[channel] = fan_config;
-		err = i2c_smbus_write_byte_data(client,
-					MAX31790_REG_FAN_CONFIG(channel),
-					fan_config);
+		if (fan_config != data->fan_config[channel]) {
+			err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
+							fan_config);
+			if (!err)
+				data->fan_config[channel] = fan_config;
+		}
 		break;
 	default:
 		err = -EOPNOTSUPP;