diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index a87dc277a5ca4937bd3ebff2b7eeb829b6b9ee1a..cb3d15bc1aeb47f2d05f00394a176c01430568e8 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -206,6 +206,7 @@ passive
 	passive trip point for the zone. Activation is done by polling with
 	an interval of 1 second.
 	Unit: millidegrees Celsius
+	Valid values: 0 (disabled) or greater than 1000
 	RW, Optional
 
 *****************************
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 65f67815902a2d18c0f1df09e48210af86002568..9073ada888354ac7cff6f0b8d38803495b5f763d 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -1052,6 +1052,13 @@ static int acpi_thermal_trip_seq_show(struct seq_file *seq, void *offset)
 				   acpi_device_bid(device));
 		}
 		seq_puts(seq, "\n");
+	} else {
+		seq_printf(seq, "passive (forced):");
+		if (tz->thermal_zone->forced_passive)
+			seq_printf(seq, "        %i C\n",
+				   tz->thermal_zone->forced_passive / 1000);
+		else
+			seq_printf(seq, "<not set>\n");
 	}
 
 	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 6f8d8f971212f39f0a86b2ac424433bf201f424b..3bc72ea57e094d5ad5a3bdae349191051331394a 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -225,6 +225,12 @@ passive_store(struct device *dev, struct device_attribute *attr,
 	if (!sscanf(buf, "%d\n", &state))
 		return -EINVAL;
 
+	/* sanity check: values below 1000 millicelcius don't make sense
+	 * and can cause the system to go into a thermal heart attack
+	 */
+	if (state && state < 1000)
+		return -EINVAL;
+
 	if (state && !tz->forced_passive) {
 		mutex_lock(&thermal_list_lock);
 		list_for_each_entry(cdev, &thermal_cdev_list, node) {
@@ -235,6 +241,8 @@ passive_store(struct device *dev, struct device_attribute *attr,
 								 cdev);
 		}
 		mutex_unlock(&thermal_list_lock);
+		if (!tz->passive_delay)
+			tz->passive_delay = 1000;
 	} else if (!state && tz->forced_passive) {
 		mutex_lock(&thermal_list_lock);
 		list_for_each_entry(cdev, &thermal_cdev_list, node) {
@@ -245,17 +253,12 @@ passive_store(struct device *dev, struct device_attribute *attr,
 								   cdev);
 		}
 		mutex_unlock(&thermal_list_lock);
+		tz->passive_delay = 0;
 	}
 
 	tz->tc1 = 1;
 	tz->tc2 = 1;
 
-	if (!tz->passive_delay)
-		tz->passive_delay = 1000;
-
-	if (!tz->polling_delay)
-		tz->polling_delay = 10000;
-
 	tz->forced_passive = state;
 
 	thermal_zone_device_update(tz);
@@ -1016,6 +1019,8 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
 		thermal_zone_device_set_polling(tz, tz->passive_delay);
 	else if (tz->polling_delay)
 		thermal_zone_device_set_polling(tz, tz->polling_delay);
+	else
+		thermal_zone_device_set_polling(tz, 0);
 	mutex_unlock(&tz->lock);
 }
 EXPORT_SYMBOL(thermal_zone_device_update);