diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
index 2f1c9d97ad211..dcf86794485fe 100644
--- a/drivers/hwmon/acpi_power_meter.c
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -84,6 +84,7 @@ struct acpi_power_meter_resource {
 	u64		power;
 	u64		cap;
 	u64		avg_interval;
+	bool		power_alarm;
 	int			sensors_valid;
 	unsigned long		sensors_last_updated;
 	struct sensor_device_attribute	sensors[NUM_SENSORS];
@@ -396,6 +397,9 @@ static ssize_t show_val(struct device *dev,
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 	u64 val = 0;
+	int ret;
+
+	guard(mutex)(&resource->lock);
 
 	switch (attr->index) {
 	case 0:
@@ -423,10 +427,17 @@ static ssize_t show_val(struct device *dev,
 			val = 0;
 		break;
 	case 6:
-		if (resource->power > resource->cap)
-			val = 1;
-		else
-			val = 0;
+		ret = update_meter(resource);
+		if (ret)
+			return ret;
+		/* need to update cap if not to support the notification. */
+		if (!(resource->caps.flags & POWER_METER_CAN_NOTIFY)) {
+			ret = update_cap(resource);
+			if (ret)
+				return ret;
+		}
+		val = resource->power_alarm || resource->power > resource->cap;
+		resource->power_alarm = resource->power > resource->cap;
 		break;
 	case 7:
 	case 8:
@@ -847,12 +858,20 @@ static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 		sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 		break;
 	case METER_NOTIFY_CAP:
+		mutex_lock(&resource->lock);
+		res = update_cap(resource);
+		if (res)
+			dev_err_once(&device->dev, "update cap failed when capping value is changed.\n");
+		mutex_unlock(&resource->lock);
 		sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 		break;
 	case METER_NOTIFY_INTERVAL:
 		sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 		break;
 	case METER_NOTIFY_CAPPING:
+		mutex_lock(&resource->lock);
+		resource->power_alarm = true;
+		mutex_unlock(&resource->lock);
 		sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 		dev_info(&device->dev, "Capping in progress.\n");
 		break;