Software

Linux Proposes Runtime Standby Like Windows Modern Standby

Linux Runtime Standby ABI Proposed
Runtime Standby ABI

• Key Takeaways:

  • Linux developer Antheas Kapenekakis has proposed a new runtime standby ABI for the Linux kernel to enable Windows-style "Modern Standby" behavior.
  • The patch series moves ACPI DSM calls from suspend completion to a transition function and exposes /sys/power/standby for userspace control.
  • The change lets the system look "asleep" (display off, power indicators) while the kernel and network remain active for background tasks.
  • The RFC and documentation are available on the Linux ACPI mailing list for review and testing.

What’s being proposed

Antheas Kapenekakis sent an RFC patch series proposing a runtime standby ABI that mirrors Microsoft Windows’ Modern Standby behavior. The goal is to let userspace trigger firmware notifications to change the hardware appearance — such as turning the display off or flashing a power LED — without fully suspending the kernel.

The proposal is aimed at devices that need to remain network-connected and responsive for background work (notifications, music playback, downloads) while appearing to be in a low-power state.

Technical changes

The core technical move in the series is to call existing ACPI Device-Specific Methods (DSMs) earlier: instead of invoking them at the end of the suspend sequence, the kernel will call them through a new transition function. That transition function will then be exposed to userspace via a new interface at /sys/power/standby.

The patches include documentation and a staged approach so the kernel plumbing can be tested before the ABI is fully exposed to userspace. As the author explains in the RFC: "This series introduces a new runtime standby ABI to allow firing Modern Standby firmware notifications that modify hardware appearance from userspace without suspending the kernel."

How it differs from earlier work

Previous efforts — notably work out of Collabora — focused on a /sys/power/lps0screenoff control for LPS0 display notifications derived from the Modern Standby specification. Kapenekakis’ series is broader, providing a general ABI and transition mechanism rather than a single control path.

Why this matters

For Linux on laptops and handhelds (including gaming handhelds), this enables finer control over power/perception trade-offs. Devices can conserve display power and present a sleeping state while maintaining connectivity and background activity.

This is particularly relevant to the gaming handheld community and vendors working on better Windows parity for Linux power behaviors.

Where to follow and test

Developers and maintainers can review the RFC and documentation on the Linux ACPI mailing list. The patch series and documentation are posted on lore.kernel.org under the linux-acpi thread for review and testing.

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