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| author | Len Brown <len.brown@intel.com> | 2007-08-14 15:49:32 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2007-08-14 15:49:32 -0400 |
| commit | c52a7419af18594426bc601d1ea346dbbcf71e28 (patch) | |
| tree | b964b0de460e3508e092efa3b69fbc7267aef735 | |
| parent | 3c1d36da1d5ed36979340efd233ddaacc45b0a02 (diff) | |
| download | linux-c52a7419af18594426bc601d1ea346dbbcf71e28.tar.gz | |
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>
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 | ||||
| -rw-r--r-- | drivers/acpi/thermal.c | 18 |
2 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 975f029be25c..18dcfdd29df0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1826,6 +1826,10 @@ and is between 256 and 4096 characters. It is defined in the file -1: disable all active trip points in all thermal zones <degrees C>: override all lowest active trip points + thermal.crt= [HW,ACPI] + -1: disable all critical trip points in all thermal zones + <degrees C>: lower all critical 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 9b31f36481d2..4c420feba207 100644 --- a/drivers/acpi/thermal.c +++ b/drivers/acpi/thermal.c @@ -79,6 +79,10 @@ static int act; 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 @@ static int acpi_thermal_get_trip_points(struct acpi_thermal *tz) 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 = |