From 72b33ef8bb1ac7f6c5a16d23304ab25ddc73d93d Mon Sep 17 00:00:00 2001 From: Len Brown Date: Sun, 12 Aug 2007 00:12:17 -0400 Subject: ACPI: thermal: create "thermal.off=1" to disable ACPI thermal support "thermal.off=1" disables all ACPI thermal support at boot time. CONFIG_ACPI_THERMAL=n can do this at build time. "# rmmod thermal" can do this at run time, as long as thermal is built as a module. WARNING: On some systems, disabling ACPI thermal support will cause the system to run hotter and reduce the lifetime of the hardware. Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a326487a3ab..de3300c9056 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1820,6 +1820,9 @@ 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.off= [HW,ACPI] + 1: disable ACPI thermal control + time Show timing data prefixed to each printk message line [deprecated, see 'printk.time'] -- cgit v1.2.3 From 730ff34de766a6fddee25ac1c32bc49c1a2fd758 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Sun, 12 Aug 2007 00:12:26 -0400 Subject: ACPI: thermal: expose "thermal.tzp=" to set global polling frequency Thermal Zone Polling frequency (_TZP) is an optional ACPI object recommending the rate that the OS should poll the associated thermal zone. If _TZP is 0, no polling should be used. If _TZP is non-zero, then the platform recommends that the OS poll the thermal zone at the specified rate. The minimum period is 30 seconds. The maximum period is 5 minutes. (note _TZP and thermal.tzp units are in deci-seconds, so _TZP = 300 corresponds to 30 seconds) If _TZP is not present, ACPI 3.0b recommends that the thermal zone be polled at an "OS provided default frequency". However, common industry practice is: 1. The BIOS never specifies any _TZP 2. High volume OS's from this century never poll any thermal zones Ie. The OS depends on the platform's ability to provoke thermal events when necessary, and the "OS provided default frequency" is "never":-) There is a proposal that ACPI 4.0 be updated to reflect common industry practice -- ie. no _TZP, no polling. The Linux kernel already follows this practice -- thermal zones are not polled unless _TZP is present and non-zero. But thermal zone polling is useful as a workaround for systems which have ACPI thermal control, but have an issue preventing thermal events. Indeed, some Linux distributions still set a non-zero thermal polling frequency for this reason. But rather than ask the user to write a polling frequency into all the /proc/acpi/thermal_zone/*/polling_frequency files, here we simply document and expose the already existing module parameter to do the same at system level, to simplify debugging those broken platforms. Note that thermal.tzp is a module-load time parameter only. Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index de3300c9056..ed7d7913af8 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1823,6 +1823,11 @@ and is between 256 and 4096 characters. It is defined in the file thermal.off= [HW,ACPI] 1: disable ACPI thermal control + thermal.tzp= [HW,ACPI] + Specify global default ACPI thermal zone polling rate + : poll all this frequency + 0: no polling (default) + time Show timing data prefixed to each printk message line [deprecated, see 'printk.time'] -- cgit v1.2.3 From a70cdc5200b0eb9fc3ef64efb29baac9b2cf2431 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Sun, 12 Aug 2007 00:12:35 -0400 Subject: ACPI: thermal: create "thermal.psv=" to override passive trip points "thermal.psv=-1" disables passive trip points for all ACPI thermal zones. "thermal.psv=C", where 'C' is degrees Celsius, overrides all existing passive trip points for all ACPI thermal zones. thermal.psv is checked at module load time, and in response to trip-point change events. Note that if the system does not deliver thermal zone temperature change events near the new trip-point, then it will not be noticed. To force your custom trip point to be noticed, you may need to enable polling: eg. thermal.tzp=3000 invokes polling every 5 minutes. Note that once passive thermal throttling is invoked, it has its own internal Thermal Sampling Period (_TSP), that is unrelated to _TZP. WARNING: disabling or raising a thermal trip point may result in increased running temperature and shorter hardware lifetime on some systems. Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ed7d7913af8..52e1c2d26a2 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1823,6 +1823,10 @@ and is between 256 and 4096 characters. It is defined in the file thermal.off= [HW,ACPI] 1: disable ACPI thermal control + thermal.psv= [HW,ACPI] + -1: disable all passive trip points + : override all passive trip points to this value + thermal.tzp= [HW,ACPI] Specify global default ACPI thermal zone polling rate : poll all this frequency -- cgit v1.2.3 From f54871456162aff557d57bec51639b1288d4a84b Mon Sep 17 00:00:00 2001 From: Len Brown Date: Sun, 12 Aug 2007 00:12:44 -0400 Subject: ACPI: thermal: create "thermal.nocrt" to disable critical actions thermal.nocrt=1 disables actions on _CRT and _HOT ACPI thermal zone trip-points. They will be marked as in /proc/acpi/thermal_zone/*/trip_points. There are two cases where this option is used: 1. Debugging a hot system crossing valid trip point. If your system fan is spinning at full speed, be sure that the vent is not clogged with dust. Many laptops have very fine thermal fins that are easily blocked. Check that the processor fan-sink is properly seated, has the proper thermal grease, and is really spinning. Check for fan related options in BIOS SETUP. Sometimes there is a performance vs quiet option. Defaults are generally the most conservative. If your fan is not spinning, yet /proc/acpi/fan/ has files in it, please file a Linux/ACPI bug. WARNING: you risk shortening the lifetime of your hardware if you use this parameter on a hot system. Note that this refers to all system components, including the disk drive. 2. Working around a cool system crossing critical trip point due to erroneous temperature reading. Try again with CONFIG_HWMON=n There is known potential for conflict between the the hwmon sub-system and the ACPI BIOS. If this fixes it, notify lm-sensors@lm-sensors.org and linux-acpi@vger.kernel.org Otherwise, file a Linux/ACPI bug, or notify just linux-acpi@vger.kernel.org. Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 52e1c2d26a2..4c7d2774d2a 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.nocrt= [HW,ACPI] + Set to disable actions on ACPI thermal zone + critical and hot trip points. + thermal.off= [HW,ACPI] 1: disable ACPI thermal control -- cgit v1.2.3 From f8707ec9643769957065405b5090e4aa64fd8214 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Sun, 12 Aug 2007 00:12:54 -0400 Subject: ACPI: thermal: create "thermal.act=" to disable or override active trip point thermal.act=-1 disables all active trip points in all ACPI thermal zones. thermal.act=C, where C > 0, overrides all lowest temperature active trip points in all thermal zones to C degrees Celsius. Raising this trip-point may allow you to keep your system silent up to a higher temperature. However, it will not allow you to raise the lowest temperature trip point above the next higher trip point (if there is one). Lowering this trip point may kick in the fan sooner. Note that overriding this trip-point will disable any BIOS attempts to implement hysteresis around the lowest temperature trip point. This may result in the fan starting and stopping frequently if temperature frequently crosses C. WARNING: raising trip points above the manufacturer's defaults may cause the system to run at higher temperature and shorten its life. Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4c7d2774d2a..06db892b558 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 + : override all lowest active trip points + thermal.nocrt= [HW,ACPI] Set to disable actions on ACPI thermal zone critical and hot trip points. -- cgit v1.2.3