2 files changed, 34 insertions, 4 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4c7d2774d2a4..06db892b558a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1820,6 +1820,10 @@ and is between 256 and 4096 characters. It is defined in the file
         thash_entries=  [KNL,NET]
                         Set number of hash buckets for TCP connection
 
+        thermal.act=    [HW,ACPI]
+                        -1: disable all active trip points in all thermal zones
+                        <degrees C>: override all lowest active trip points
+
         thermal.nocrt=  [HW,ACPI]
                         Set to disable actions on ACPI thermal zone
                         critical and hot trip points.
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 57d05ff44dd1..3521c37bbd33 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -74,6 +74,10 @@ MODULE_AUTHOR("Paul Diefenbaugh");
 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
 MODULE_LICENSE("GPL");
 
+static int act;
+module_param(act, int, 0644);
+MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.\n");
+
 static int tzp;
 module_param(tzp, int, 0444);
 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.\n");
@@ -405,11 +409,33 @@ static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 
                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 
-                status =
-                    acpi_evaluate_integer(tz->device->handle, name, NULL,
-                                          &tz->trips.active[i].temperature);
-                if (ACPI_FAILURE(status))
+                if (act == -1)
+                        break;  /* disable all active trip points */
+
+                status = acpi_evaluate_integer(tz->device->handle,
+                        name, NULL, &tz->trips.active[i].temperature);
+
+                if (ACPI_FAILURE(status)) {
+                        if (i == 0)     /* no active trip points */
+                                break;
+                        if (act <= 0)   /* no override requested */
+                                break;
+                        if (i == 1) {   /* 1 trip point */
+                                tz->trips.active[0].temperature =
+                                        CELSIUS_TO_KELVIN(act);
+                        } else {        /* multiple trips */
+                                /*
+                                 * Don't allow override higher than
+                                 * the next higher trip point
+                                 */
+                                tz->trips.active[i - 1].temperature =
+                                    (tz->trips.active[i - 2].temperature <
+                                        CELSIUS_TO_KELVIN(act) ?
+                                        tz->trips.active[i - 2].temperature :
+                                        CELSIUS_TO_KELVIN(act));
+                        }
                         break;
+                }
 
                 name[2] = 'L';
                 status =