thermal.act=-1 disables all active trip points
in all ACPI thermal zones.

thermal.act=C, where C > 0, overrides all first active trip points
in all thermal zones to C degrees Celcius.

Note, overriding this trip-point will disable any BIOS attempts
to implement hysterisis around AC0, and may result in the fan
starting and stopping frequently if temperature frequently crosses C.

Signed-off-by: Len Brown <[EMAIL PROTECTED]>
---
 Documentation/kernel-parameters.txt |    4 ++++
 drivers/acpi/thermal.c              |   20 ++++++++++++++++----
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/Documentation/kernel-parameters.txt 
b/Documentation/kernel-parameters.txt
index 897bb63..a82d46f 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 1642980..2b48ab9 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 +409,19 @@ 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)) {
+                       /* override last valid trip point */
+                       if ((i > 0) && (act > 0))
+                               tz->trips.active[i - 1].temperature =
+                                       CELSIUS_TO_KELVIN(act);
                        break;
+               }
 
                name[2] = 'L';
                status =
-- 
1.5.3.rc4.29.g74276
-
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to