alexis-opolka / acpi_call_made_easy

A fork of @biji /acpi_call with more instructions and tweaks following Fedora's guidelines.

ACPI_CALL - A Linux Kernel

A simple kernel module that enables you to call ACPI methods by writing the method name followed by arguments to /proc/acpi/call.

acpi_call is used from the terminal, if you're afraid or simply want a graphical experience, see the dedicated section below.

⚠️ Caution ! ⚠️

This module is to be considered a proof-of-concept and has been superseeded by projects like bbswitch. It allows you to tamper with your system and should be used with caution.

The commands work on the author's ASUS K52J notebook, but may not work for you. See linux-hybrid-graphics.blogspot.com or try running the provided scripts (e.g. examples/turn_off_gpu.sh).

It SHOULD be ok to test all of the methods, until you see a drop in battery drain rate (grep rate /proc/acpi/battery/BAT0/state), however it comes with NO WARRANTY - it may hang your computer/laptop, fail to work, etc.

Installation

Usage

You can call acpi_call this way:

echo '<call>' | sudo tee /proc/acpi/call

You can then retrieve the result of the call by checking your dmesg or:

sudo cat /proc/acpi/call

An example to turn off discrete graphics card in a dual graphics environment (like NVIDIA Optimus):

# turn off discrete graphics card
echo '\_SB.PCI0.PEG1.GFX0.DOFF' > /proc/acpi/call
# turn it back on
echo '\_SB.PCI0.PEG1.GFX0.DON' > /proc/acpi/call

You can pass parameters to acpi_call by writing them after the method, separated by single space. Currently, you can pass the following parameter types:

• ACPI_INTEGER - by writing NNN or 0xNNN, where NNN is an integer/hex
• ACPI_STRING - by enclosing the string in quotes: "hello, world"
• ACPI_BUFFER - by writing bXXXX, where XXXX is a hex string without spaces, or by writing { b1, b2, b3, b4 }, where b1-4 are integers

The status after a call can be read back from /proc/acpi/call:

• 'not called' - nothing to report
• 'Error: ' - the call failed
• '0xNN' - the call succeeded, and returned an integer
• '"..."' - the call succeeded, and returned a string
• '{0xNN, ...}' - the call succeeded, and returned a buffer
• '[...]' - the call succeeded, and returned a package which may contain the above types (integer, string and buffer) and other package types

Graphical interfaces

If you found this too difficult for you or simply want a graphical experience give a try to these programs provided by Marco Dalla Libera:

• acpi_call_GUI (Ubuntu and other debian-based distributions)
• acpi_call_GUI_Fedora (Fedora version)

Issues, Pull Requests and Contributions

If you want to open an issue, propose a fix or just want to improve this kernel module overall, you have two choices:

• Open an Issue or Pull Request on this repository regarding changes concerning modifications made on this fork

• Open an Issue or Pull Request on the original repository regarding problems with the original code.

  Please mention me (i.e. @alexis-opolka) if you open an issue on the original repository and want a fix to appear on my fork. I will greatly appreciate it. ^-^

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Copyright

Copyright © 2010: Michal Kottman
Copyright © Biji
Copyright © 2023 Alexis Opolka

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.