Related articles * [acpid](/index.php/Acpid "Acpid") * [DSDT](/index.php/DSDT "DSDT") From [ACPI site](http://www.acpi.info/): *ACPI (Advanced Configuration and Power Interface) is an open industry specification co-developed by Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba.* ACPI modules are kernel modules for different ACPI parts. They enable special ACPI functions or add information to `/proc` or `/sys`. These information can be parsed by [acpid](/index.php/Acpid "Acpid") for events or other monitoring applications. ## Contents * [1 Which modules are available?](#Which_modules_are_available.3F) * [2 How to select the correct ones](#How_to_select_the_correct_ones) * [3 Getting information](#Getting_information) * [4 Troubleshooting](#Troubleshooting) * [4.1 DSDT fix](#DSDT_fix) * [4.2 ACPI fix for notebooks](#ACPI_fix_for_notebooks) * [5 See also](#See_also) ## Which modules are available? This is a small list and summary of ACPI kernel modules: * ac (power connector status) * asus-laptop (useful on ASUS/medion laptops) * battery (battery status) * bay (bay status) * button (catch button events, like LID or POWER BUTTON) * container (container status) * dock (docking station status) * fan (fan status) * i2c_ec (EC SMBUs driver) * thinkpad_acpi (useful on Lenovo Thinkpad laptops) * processor (processor status) * sbs (smart battery status) * thermal (status of thermal sensors) * toshiba_acpi (useful for Toshiba laptops) * video (status of video devices) complete list of your running kernel: `$ ls -l /usr/lib/modules/$(uname -r)/kernel/drivers/acpi` ``` total 112 -rw-r--r-- 1 root root 2808 Aug 29 23:58 ac.ko.gz -rw-r--r-- 1 root root 3021 Aug 29 23:58 acpi_ipmi.ko.gz -rw-r--r-- 1 root root 3354 Aug 29 23:58 acpi_memhotplug.ko.gz -rw-r--r-- 1 root root 4628 Aug 29 23:58 acpi_pad.ko.gz drwxr-xr-x 2 root root 4096 Aug 29 23:59 apei -rw-r--r-- 1 root root 7120 Aug 29 23:58 battery.ko.gz -rw-r--r-- 1 root root 3700 Aug 29 23:58 button.ko.gz -rw-r--r-- 1 root root 2181 Aug 29 23:58 container.ko.gz -rw-r--r-- 1 root root 1525 Aug 29 23:58 custom_method.ko.gz -rw-r--r-- 1 root root 1909 Aug 29 23:58 ec_sys.ko.gz -rw-r--r-- 1 root root 2001 Aug 29 23:58 fan.ko.gz -rw-r--r-- 1 root root 1532 Aug 29 23:58 hed.ko.gz -rw-r--r-- 1 root root 3241 Aug 29 23:58 pci_slot.ko.gz -rw-r--r-- 1 root root 17742 Aug 29 23:58 processor.ko.gz -rw-r--r-- 1 root root 3073 Aug 29 23:58 sbshc.ko.gz -rw-r--r-- 1 root root 7098 Aug 29 23:58 sbs.ko.gz -rw-r--r-- 1 root root 6311 Aug 29 23:58 thermal.ko.gz -rw-r--r-- 1 root root 8891 Aug 29 23:58 video.ko.gz ``` ## How to select the correct ones You have to try yourself which module works for your machine: `# modprobe ` then check if the module is supported on your hardware by using `$ dmesg` **Tip:** It may help to add a grep text search to narrow your results. ``` $ dmesg | grep acpi [ 0.000000] ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled) [ 0.000000] ACPI: LAPIC (acpi_id[0x01] lapic_id[0x04] enabled) [ 0.000000] ACPI: LAPIC (acpi_id[0x02] lapic_id[0x01] enabled) [ 0.000000] ACPI: LAPIC (acpi_id[0x03] lapic_id[0x05] enabled) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x00] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x02] high edge lint[0x1]) [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x03] high edge lint[0x1]) [ 5.066752] ACPI: acpi_idle yielding to intel_idle [ 5.438998] acpi device:04: registered as cooling_device4 ``` Add the working ones to configuration files in `/etc/modules-load.d`. `/etc/modules-load.d` is described in [Kernel modules#Automatic module handling](/index.php/Kernel_modules#Automatic_module_handling "Kernel modules"). ## Getting information To read out battery information, you can simply [install](/index.php/Install "Install") the package [acpi](https://www.archlinux.org/packages/?name=acpi) in the [official repositories](/index.php/Official_repositories "Official repositories") and run: ``` acpi -i ``` Using `/proc` to store ACPI information has been discouraged and deprecated since Linux 2.6.24\. The same data is available in `/sys` now, and interested parties can (should) subscribe to ACPI events from the kernel via netlink. For example, for battery: ``` /sys/class/power_supply/BAT0/ ``` ## Troubleshooting ### DSDT fix If problems with power management persist despite having loaded the proper modules, a Linux-unfriendly [DSDT](https://en.wikipedia.org/wiki/DSDT#ACPI_Tables "wikipedia:DSDT") might be the cause. See the wiki article on [DSDT](/index.php/DSDT "DSDT"). ### ACPI fix for notebooks Sometimes you see "ACPI: EC: input buffer is not empty, aborting transaction". This is a problem with ACPI, more specifically an incompatibility of the BIOS. There may be four ways to solve this issue: * If available, update the BIOS. * Use `acpi=off` as [kernel parameter](/index.php/Kernel_parameter "Kernel parameter"), however this will kill all ACPI functionality like battery charging and power saving. * In some cases disabeling [DPMS](/index.php/DPMS "DPMS") has been reported to solve the issue [[1]](https://ubuntuforums.org/showthread.php?p=8030130#10). However, screen brightness may no longer be fully controllable: ``` $ xset dpms force off ``` * Build a custom [kernel](/index.php/Kernel "Kernel") with patches of [bugs.launchpad.net](https://bugs.launchpad.net/ubuntu/+source/linux/+bug/578506). ## See also * [Wikipedia:Advanced Configuration and Power Interface](https://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface "wikipedia:Advanced Configuration and Power Interface")