ACPI: thermal: create "thermal.crt=C" bootparam
Some hardware will malfunction at a temperature below
the BIOS provided critical shutdown threshold.
This hook allows moving the critical trip points down
to a temperature which provokes a graceful shutdown
before the hardware malfunction.
http://bugzilla.kernel.org/show_bug.cgi?id=8884
WARNING: A trip-point override will not get noticed
until the system delivers a temperature change event,
or unless thermal zone polling is enabled.
eg. "thermal.tzp=10"
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 9b31f36..4c420fe 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -79,6 +79,10 @@
module_param(act, int, 0644);
MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
+static int crt;
+module_param(crt, int, 0644);
+MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
+
static int tzp;
module_param(tzp, int, 0444);
MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
@@ -340,6 +344,20 @@
tz->trips.critical.temperature));
}
+ if (tz->trips.critical.flags.valid == 1) {
+ if (crt == -1) {
+ tz->trips.critical.flags.valid = 0;
+ } else if (crt > 0) {
+ unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
+
+ /*
+ * Allow override to lower critical threshold
+ */
+ if (crt_k < tz->trips.critical.temperature)
+ tz->trips.critical.temperature = crt_k;
+ }
+ }
+
/* Critical Sleep (optional) */
status =
