Linux 5.7 Getting A "Tiny Power Button" Driver

Written by Michael Larabel in Linux Kernel on 14 February 2020 at 03:33 AM EST. 4 Comments
LINUX KERNEL
A new driver already queued in the power management code for the Linux 5.7 cycle not opening up until April is a "tiny power button" driver.

This ACPI tiny power button driver is not for a physically tiny power button, but rather a simple ACPI power button driver out of Intel intended for virtual machines and more basic than the generic ACPI button driver given the limited scope of VMs.

Virtual machines tend to rely on simulated ACPI power button events for having the VM power off gracefully but can rely on a daemon like acpid or systemd-logind for processing the said event. With the APCI tiny power button driver, the event from the VM is handled directly and immediately signals the init process. The goal of the tiny power button driver is to decrease startup time and reduce VM image complexity.

More details via the patch series. This also serves as a basic example of a Linux kernel driver at just 46 lines of code.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via MichaelLarabel.com.

Popular News This Week