IBM ThinkPad ACPI Extras Driver Version 0.12 17 August 2005 Borislav Deianov http://ibm-acpi.sf.net/ This is a Linux ACPI driver for the IBM ThinkPad laptops. It supports various features of these laptops which are accessible through the ACPI framework but not otherwise supported by the generic Linux ACPI drivers. Status ------ The features currently supported are the following (see below for detailed description): - Fn key combinations - Bluetooth enable and disable - video output switching, expansion control - ThinkLight on and off - limited docking and undocking - UltraBay eject - CMOS control - LED control - ACPI sounds - temperature sensors - Experimental: embedded controller register dump - LCD brightness control - Volume control - Experimental: fan speed, fan enable/disable - Experimental: WAN enable and disable A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure reports, especially if they add to or correct the compatibility table. Please include the following information in your report: - ThinkPad model name - a copy of your DSDT, from /proc/acpi/dsdt - which driver features work and which don't - the observed behavior of non-working features Any other comments or patches are also more than welcome. Installation ------------ If you are compiling this driver as included in the Linux kernel sources, simply enable the CONFIG_ACPI_IBM option (Power Management / ACPI / IBM ThinkPad Laptop Extras). Features -------- The driver creates the /proc/acpi/ibm directory. There is a file under that directory for each feature described below. Note that while the driver is still in the alpha stage, the exact proc file format and commands supported by the various features is guaranteed to change frequently. Driver version -- /proc/acpi/ibm/driver --------------------------------------- The driver name and version. No commands can be written to this file. Hot keys -- /proc/acpi/ibm/hotkey --------------------------------- Without this driver, only the Fn-F4 key (sleep button) generates an ACPI event. With the driver loaded, the hotkey feature enabled and the mask set (see below), the various hot keys generate ACPI events in the following format: ibm/hotkey HKEY 00000080 0000xxxx The last four digits vary depending on the key combination pressed. All labeled Fn-Fx key combinations generate distinct events. In addition, the lid microswitch and some docking station buttons may also generate such events. The following commands can be written to this file: echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature echo 0xffff > /proc/acpi/ibm/hotkey -- enable all possible hot keys echo 0x0000 > /proc/acpi/ibm/hotkey -- disable all possible hot keys ... any other 4-hex-digit mask ... echo reset > /proc/acpi/ibm/hotkey -- restore the original mask The bit mask allows some control over which hot keys generate ACPI events. Not all bits in the mask can be modified. Not all bits that can be modified do anything. Not all hot keys can be individually controlled by the mask. Most recent ThinkPad models honor the following bits (assuming the hot keys feature has been enabled): key bit behavior when set behavior when unset Fn-F3 always generates ACPI event Fn-F4 always generates ACPI event Fn-F5 0010 generate ACPI event enable/disable Bluetooth Fn-F7 0040 generate ACPI event switch LCD and external display Fn-F8 0080 generate ACPI event expand screen or none Fn-F9 0100 generate ACPI event none Fn-F12 always generates ACPI event Some models do not support all of the above. For example, the T30 does not support Fn-F5 and Fn-F9. Other models do not support the mask at all. On those models, hot keys cannot be controlled individually. Note that enabling ACPI events for some keys prevents their default behavior. For example, if events for Fn-F5 are enabled, that key will no longer enable/disable Bluetooth by itself. This can still be done from an acpid handler for the ibm/hotkey event. Note also that not all Fn key combinations are supported through ACPI. For example, on the X40, the brightness, volume and "Access IBM" buttons do not generate ACPI events even with this driver. They *can* be used through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/ Bluetooth -- /proc/acpi/ibm/bluetooth ------------------------------------- This feature shows the presence and current state of a Bluetooth device. If Bluetooth is installed, the following commands can be used: echo enable > /proc/acpi/ibm/bluetooth echo disable > /proc/acpi/ibm/bluetooth Video output control -- /proc/acpi/ibm/video -------------------------------------------- This feature allows control over the devices used for video output - LCD, CRT or DVI (if available). The following commands are available: echo lcd_enable > /proc/acpi/ibm/video echo lcd_disable > /proc/acpi/ibm/video echo crt_enable > /proc/acpi/ibm/video echo crt_disable > /proc/acpi/ibm/video echo dvi_enable > /proc/acpi/ibm/video echo dvi_disable > /proc/acpi/ibm/video echo auto_enable > /proc/acpi/ibm/video echo auto_disable > /proc/acpi/ibm/video echo expand_toggle > /proc/acpi/ibm/video echo video_switch > /proc/acpi/ibm/video Each video output device can be enabled or disabled individually. Reading /proc/acpi/ibm/video shows the status of each device. Automatic video switching can be enabled or disabled. When automatic video switching is enabled, certain events (e.g. opening the lid, docking or undocking) cause the video output device to change automatically. While this can be useful, it also causes flickering and, on the X40, video corruption. By disabling automatic switching, the flickering or video corruption can be avoided. The video_switch command cycles through the available video outputs (it simulates the behavior of Fn-F7). Video expansion can be toggled through this feature. This controls whether the display is expanded to fill the entire LCD screen when a mode with less than full resolution is used. Note that the current video expansion status cannot be determined through this feature. Note that on many models (particularly those using Radeon graphics chips) the X driver configures the video card in a way which prevents Fn-F7 from working. This also disables the video output switching features of this driver, as it uses the same ACPI methods as Fn-F7. Video switching on the console should still work. UPDATE: There's now a patch for the X.org Radeon driver which addresses this issue. Some people are reporting success with the patch while others are still having problems. For more information: https://bugs.freedesktop.org/show_bug.cgi?id=2000 ThinkLight control -- /proc/acpi/ibm/light ------------------------------------------ The current status of the ThinkLight can be found in this file. A few models which do not make the status available will show it as "unknown". The available commands are: echo on > /proc/acpi/ibm/light echo off > /proc/acpi/ibm/light Docking / undocking -- /proc/acpi/ibm/dock ------------------------------------------ Docking and undocking (e.g. with the X4 UltraBase) requires some actions to be taken by the operating system to safely make or break the electrical connections with the dock. The docking feature of this driver generates the following ACPI events: ibm/dock GDCK 00000003 00000001 -- eject request ibm/dock GDCK 00000003 00000002 -- undocked ibm/dock GDCK 00000000 00000003 -- docked NOTE: These events will only be generated if the laptop was docked when originally booted. This is due to the current lack of support for hot plugging of devices in the Linux ACPI framework. If the laptop was booted while not in the dock, the following message is shown in the logs: Mar 17 01:42:34 aero kernel: ibm_acpi: dock device not present In this case, no dock-related events are generated but the dock and undock commands described below still work. They can be executed manually or triggered by Fn key combinations (see the example acpid configuration files included in the driver tarball package available on the web site). When the eject request button on the dock is pressed, the first event above is generated. The handler for this event should issue the following command: echo undock > /proc/acpi/ibm/dock After the LED on the dock goes off, it is safe to eject the laptop. Note: if you pressed this key by mistake, go ahead and eject the laptop, then dock it back in. Otherwise, the dock may not function as expected. When the laptop is docked, the third event above is generated. The handler for this event should issue the following command to fully enable the dock: echo dock > /proc/acpi/ibm/dock The contents of the /proc/acpi/ibm/dock file shows the current status of the dock, as provided by the ACPI framework. The docking support in this driver does not take care of enabling or disabling any other devices you may have attached to the dock. For example, a CD drive plugged into the UltraBase needs to be disabled or enabled separately. See the provided example acpid configuration files for how this can be accomplished. There is no support yet for PCI devices that may be attached to a docking station, e.g. in the ThinkPad Dock II. The driver currently does not recognize, enable or disable such devices. This means that the only docking stations currently supported are the X-series UltraBase docks and "dumb" port replicators like the Mini Dock (the latter don't need any ACPI support, actually). UltraBay eject -- /proc/acpi/ibm/bay ------------------------------------ Inserting or ejecting an UltraBay device requires some actions to be taken by the operating system to safely make or break the electrical connections with the device. This feature generates the following ACPI events: ibm/bay MSTR 00000003 00000000 -- eject request ibm/bay MSTR 00000001 00000000 -- eject lever inserted NOTE: These events will only be generated if the UltraBay was present when the laptop was originally booted (on the X series, the UltraBay is in the dock, so it may not be present if the laptop was undocked). This is due to the current lack of support for hot plugging of devices in the Linux ACPI framework. If the laptop was booted without the UltraBay, the following message is shown in the logs: Mar 17 01:42:34 aero kernel: ibm_acpi: bay device not present In this case, no bay-related events are generated but the eject command described below still works. It can be executed manually or triggered by a hot key combination. Sliding the eject lever generates the first event shown above. The handler for this event should take whatever actions are necessary to shut down the device in the UltraBay (e.g. call idectl), then issue the following command: echo eject > /proc/acpi/ibm/bay After the LED on the UltraBay goes off, it is safe to pull out the device. When the eject lever is inserted, the second event above is generated. The handler for this event should take whatever actions are necessary to enable the UltraBay device (e.g. call idectl). The contents of the /proc/acpi/ibm/bay file shows the current status of the UltraBay, as provided by the ACPI framework. EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use this feature, you need to supply the experimental=1 parameter when loading the module): These models do not have a button near the UltraBay device to request a hot eject but rather require the laptop to be put to sleep (suspend-to-ram) before the bay device is ejected or inserted). The sequence of steps to eject the device is as follows: echo eject > /proc/acpi/ibm/bay put the ThinkPad to sleep remove the drive resume from sleep cat /proc/acpi/ibm/bay should show that the drive was removed On the A3x, both the UltraBay 2000 and UltraBay Plus devices are supported. Use "eject2" instead of "eject" for the second bay. Note: the UltraBay eject support on the 600e/x, A22p and A3x is EXPERIMENTAL and may not work as expected. USE WITH CAUTION! CMOS control -- /proc/acpi/ibm/cmos ----------------------------------- This feature is used internally by the ACPI firmware to control the ThinkLight on most newer ThinkPad models. It may also control LCD brightness, sounds volume and more, but only on some models. The commands are non-negative integer numbers: echo 0 >/proc/acpi/ibm/cmos echo 1 >/proc/acpi/ibm/cmos echo 2 >/proc/acpi/ibm/cmos ... The range of valid numbers is 0 to 21, but not all have an effect and the behavior varies from model to model. Here is the behavior on the X40 (tpb is the ThinkPad Buttons utility): 0 - no effect but tpb reports "Volume down" 1 - no effect but tpb reports "Volume up" 2 - no effect but tpb reports "Mute on" 3 - simulate pressing the "Access IBM" button 4 - LCD brightness up 5 - LCD brightness down 11 - toggle screen expansion 12 - ThinkLight on 13 - ThinkLight off 14 - no effect but tpb reports ThinkLight status change LED control -- /proc/acpi/ibm/led --------------------------------- Some of the LED indicators can be controlled through this feature. The available commands are: echo ' on' >/proc/acpi/ibm/led echo ' off' >/proc/acpi/ibm/led echo ' blink' >/proc/acpi/ibm/led The range is 0 to 7. The set of LEDs that can be controlled varies from model to model. Here is the mapping on the X40: 0 - power 1 - battery (orange) 2 - battery (green) 3 - UltraBase 4 - UltraBay 7 - standby All of the above can be turned on and off and can be made to blink. ACPI sounds -- /proc/acpi/ibm/beep ---------------------------------- The BEEP method is used internally by the ACPI firmware to provide audible alerts in various situations. This feature allows the same sounds to be triggered manually. The commands are non-negative integer numbers: echo >/proc/acpi/ibm/beep The valid range is 0 to 17. Not all numbers trigger sounds and the sounds vary from model to model. Here is the behavior on the X40: 0 - stop a sound in progress (but use 17 to stop 16) 2 - two beeps, pause, third beep ("low battery") 3 - single beep 4 - high, followed by low-pitched beep ("unable") 5 - single beep 6 - very high, followed by high-pitched beep ("AC/DC") 7 - high-pitched beep 9 - three short beeps 10 - very long beep 12 - low-pitched beep 15 - three high-pitched beeps repeating constantly, stop with 0 16 - one medium-pitched beep repeating constantly, stop with 17 17 - stop 16 Temperature sensors -- /proc/acpi/ibm/thermal --------------------------------------------- Most ThinkPads include six or more separate temperature sensors but only expose the CPU temperature through the standard ACPI methods. This feature shows readings from up to eight different sensors on older ThinkPads, and it has experimental support for up to sixteen different sensors on newer ThinkPads. Readings from sensors that are not available return -128. No commands can be written to this file. EXPERIMENTAL: The 16-sensors feature is marked EXPERIMENTAL because the implementation directly accesses hardware registers and may not work as expected. USE WITH CAUTION! To use this feature, you need to supply the experimental=1 parameter when loading the module. When EXPERIMENTAL mode is enabled, reading the first 8 sensors on newer ThinkPads will also use an new experimental thermal sensor access mode. For example, on the X40, a typical output may be: temperatures: 42 42 45 41 36 -128 33 -128 EXPERIMENTAL: On the T43/p, a typical output may be: temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128 The mapping of thermal sensors to physical locations varies depending on system-board model (and thus, on ThinkPad model). http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that tries to track down these locations for various models. Most (newer?) models seem to follow this pattern: 1: CPU 2: (depends on model) 3: (depends on model) 4: GPU 5: Main battery: main sensor 6: Bay battery: main sensor 7: Main battery: secondary sensor 8: Bay battery: secondary sensor 9-15: (depends on model) For the R51 (source: Thomas Gruber): 2: Mini-PCI 3: Internal HDD For the T43, T43/p (source: Shmidoax/Thinkwiki.org) http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p 2: System board, left side (near PCMCIA slot), reported as HDAPS temp 3: PCMCIA slot 9: MCH (northbridge) to DRAM Bus 10: ICH (southbridge), under Mini-PCI card, under touchpad 11: Power regulator, underside of system board, below F2 key The A31 has a very atypical layout for the thermal sensors (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31) 1: CPU 2: Main Battery: main sensor 3: Power Converter 4: Bay Battery: main sensor 5: MCH (northbridge) 6: PCMCIA/ambient 7: Main Battery: secondary sensor 8: Bay Battery: secondary sensor EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump ------------------------------------------------------------------------ This feature is marked EXPERIMENTAL because the implementation directly accesses hardware registers and may not work as expected. USE WITH CAUTION! To use this feature, you need to supply the experimental=1 parameter when loading the module. This feature dumps the values of 256 embedded controller registers. Values which have changed since the last time the registers were dumped are marked with a star: [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a This feature can be used to determine the register holding the fan speed on some models. To do that, do the following: - make sure the battery is fully charged - make sure the fan is running - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so The first step makes sure various charging-related values don't vary. The second ensures that the fan-related values do vary, since the fan speed fluctuates a bit. The third will (hopefully) mark the fan register with a star: [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a Another set of values that varies often is the temperature readings. Since temperatures don't change vary fast, you can take several quick dumps to eliminate them. You can use a similar method to figure out the meaning of other embedded controller registers - e.g. make sure nothing else changes except the charging or discharging battery to determine which registers contain the current battery capacity, etc. If you experiment with this, do send me your results (including some complete dumps with a description of the conditions when they were taken.) LCD brightness control -- /proc/acpi/ibm/brightness --------------------------------------------------- This feature allows software control of the LCD brightness on ThinkPad models which don't have a hardware brightness slider. The available commands are: echo up >/proc/acpi/ibm/brightness echo down >/proc/acpi/ibm/brightness echo 'level ' >/proc/acpi/ibm/brightness The number range is 0 to 7, although not all of them may be distinct. The current brightness level is shown in the file. Volume control -- /proc/acpi/ibm/volume --------------------------------------- This feature allows volume control on ThinkPad models which don't have a hardware volume knob. The available commands are: echo up >/proc/acpi/ibm/volume echo down >/proc/acpi/ibm/volume echo mute >/proc/acpi/ibm/volume echo 'level ' >/proc/acpi/ibm/volume The number range is 0 to 15 although not all of them may be distinct. The unmute the volume after the mute command, use either the up or down command (the level command will not unmute the volume). The current volume level and mute state is shown in the file. EXPERIMENTAL: fan speed, fan enable/disable -- /proc/acpi/ibm/fan ----------------------------------------------------------------- This feature is marked EXPERIMENTAL because the implementation directly accesses hardware registers and may not work as expected. USE WITH CAUTION! To use this feature, you need to supply the experimental=1 parameter when loading the module. This feature attempts to show the current fan speed, control mode and other fan data that might be available. The speed is read directly from the hardware registers of the embedded controller. This is known to work on later R, T and X series ThinkPads but may show a bogus value on other models. Most ThinkPad fans work in "levels". Level 0 stops the fan. The higher the level, the higher the fan speed, although adjacent levels often map to the same fan speed. 7 is the highest level, where the fan reaches the maximum recommended speed. Level "auto" means the EC changes the fan level according to some internal algorithm, usually based on readings from the thermal sensors. Level "disengaged" means the EC disables the speed-locked closed-loop fan control, and drives the fan as fast as it can go, which might exceed hardware limits, so use this level with caution. The fan usually ramps up or down slowly from one speed to another, and it is normal for the EC to take several seconds to react to fan commands. The fan may be enabled or disabled with the following commands: echo enable >/proc/acpi/ibm/fan echo disable >/proc/acpi/ibm/fan Placing a fan on level 0 is the same as disabling it. Enabling a fan will try to place it in a safe level if it is too slow or disabled. WARNING WARNING WARNING: do not leave the fan disabled unless you are monitoring all of the temperature sensor readings and you are ready to enable it if necessary to avoid overheating. An enabled fan in level "auto" may stop spinning if the EC decides the ThinkPad is cool enough and doesn't need the extra airflow. This is normal, and the EC will spin the fan up if the varios thermal readings rise too much. On the X40, this seems to depend on the CPU and HDD temperatures. Specifically, the fan is turned on when either the CPU temperature climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The fan is turned off when the CPU temperature drops to 49 degrees and the HDD temperature drops to 41 degrees. These thresholds cannot currently be controlled. The fan level can be controlled with the command: echo 'level ' > /proc/acpi/ibm/thermal Where is an integer from 0 to 7, or one of the words "auto" or "disengaged" (without the quotes). Not all ThinkPads support the "auto" and "disengaged" levels. On the X31 and X40 (and ONLY on those models), the fan speed can be controlled to a certain degree. Once the fan is running, it can be forced to run faster or slower with the following command: echo 'speed ' > /proc/acpi/ibm/thermal The sustainable range of fan speeds on the X40 appears to be from about 3700 to about 7350. Values outside this range either do not have any effect or the fan speed eventually settles somewhere in that range. The fan cannot be stopped or started with this command. The ThinkPad's ACPI DSDT code will reprogram the fan on its own when certain conditions are met. It will override any fan programming done through ibm-acpi. EXPERIMENTAL: WAN -- /proc/acpi/ibm/wan --------------------------------------- This feature is marked EXPERIMENTAL because the implementation directly accesses hardware registers and may not work as expected. USE WITH CAUTION! To use this feature, you need to supply the experimental=1 parameter when loading the module. This feature shows the presence and current state of a WAN (Sierra Wireless EV-DO) device. If WAN is installed, the following commands can be used: echo enable > /proc/acpi/ibm/wan echo disable > /proc/acpi/ibm/wan It was tested on a Lenovo Thinkpad X60. It should probably work on other Thinkpad models which come with this module installed. Multiple Commands, Module Parameters ------------------------------------ Multiple commands can be written to the proc files in one shot by separating them with commas, for example: echo enable,0xffff > /proc/acpi/ibm/hotkey echo lcd_disable,crt_enable > /proc/acpi/ibm/video Commands can also be specified when loading the ibm_acpi module, for example: modprobe ibm_acpi hotkey=enable,0xffff video=auto_disable The ibm-acpi kernel driver can be programmed to revert the fan level to a safe setting if userspace does not issue one of the fan commands: "enable", "disable", "level" or "watchdog" within a configurable ammount of time. To do this, use the "watchdog" command. echo 'watchdog ' > /proc/acpi/ibm/fan Interval is the ammount of time in seconds to wait for one of the above mentioned fan commands before reseting the fan level to a safe one. If set to zero, the watchdog is disabled (default). When the watchdog timer runs out, it does the exact equivalent of the "enable" fan command. Note that the watchdog timer stops after it enables the fan. It will be rearmed again automatically (using the same interval) when one of the above mentioned fan commands is received. The fan watchdog is, therefore, not suitable to protect against fan mode changes made through means other than the "enable", "disable", and "level" fan commands. Example Configuration --------------------- The ACPI support in the kernel is intended to be used in conjunction with a user-space daemon, acpid. The configuration files for this daemon control what actions are taken in response to various ACPI events. An example set of configuration files are included in the config/ directory of the tarball package available on the web site. Note that these are provided for illustration purposes only and may need to be adapted to your particular setup. The following utility scripts are used by the example action scripts (included with ibm-acpi for completeness): /usr/local/sbin/idectl -- from the hdparm source distribution, see http://www.ibiblio.org/pub/Linux/system/hardware /usr/local/sbin/laptop_mode -- from the Linux kernel source distribution, see Documentation/laptop-mode.txt /sbin/service -- comes with Redhat/Fedora distributions /usr/sbin/hibernate -- from the Software Suspend 2 distribution, see http://softwaresuspend.berlios.de/ Toan T Nguyen notes that Suse uses the powersave program to suspend ('powersave --suspend-to-ram') or hibernate ('powersave --suspend-to-disk'). This means that the hibernate script is not needed on that distribution. Henrik Brix Andersen has written a Gentoo ACPI event handler script for the X31. You can get the latest version from http://dev.gentoo.org/~brix/files/x31.sh David Schweikert has written an alternative blank.sh script which works on Debian systems. This scripts has now been extended to also work on Fedora systems and included as the default blank.sh in the distribution.