Hans de Goede has posted an RFC (Request For Comments) patch series on the Linux kernel mailing list that goes after one of the thorniest parts of Arm laptop support: how to boot and describe the hardware on Qualcomm Snapdragon X machines. The proposal is called DeviceTree-ACPI hybrid mode, and the point is to stop treating Device Tree and ACPI as mutually exclusive.
De Goede is no stranger to this work. For years at Red Hat he drove a large share of the Linux laptop improvements for AMD and Intel x86_64 hardware. He left Red Hat last year and joined Qualcomm to push their open-source and Linux support, so this series comes from someone who knows the territory well.
What happens today with Snapdragon X and Linux
Snapdragon X1 and X2 laptops on Linux rely on Device Tree alone to describe the hardware, like most Arm single-board computers. Windows 11 on Arm, by contrast, boots using ACPI. The catch is that the ACPI tables on these machines are inadequate for Linux to boot from them on its own. Information is missing, so the kernel ignores them entirely.
The current behavior is blunt. As soon as the kernel boots with a populated Device Tree, the arch/arm64 code sets acpi_disabled=1 and the whole ACPI subsystem is turned off. De Goede frames it like this in his RFC: on WoA Snapdragon laptops, where the factory Windows install actually boots using those tables, disabling ACPI completely is not necessarily what you want. Even when booting via Device Tree, it could still be worth parsing the ACPI tables and making the ACPI fwnodes available for device drivers to use.
The hybrid mode and what already works
That is exactly the DT-ACPI hybrid mode: boot with Device Tree, but keep ACPI parsed and available. For now it is an experiment, and the author presents it as a possible way to speed up the effort of getting Linux running on the Snapdragon laptops already on sale.
It is not just theory. With the posted patches, De Goede tested a Lenovo ThinkPad T14s Gen 6 and managed to remove the Device Tree descriptions for the keyboard and touchpad so that ACPI instantiated them instead. It worked. The mode also opens up practical things: running acpidump to explore the ACPI tables of systems booted via Device Tree, or letting drivers reach ACPI data in the cases where that helps.
Who should care
The line that will get the most attention is the last one in De Goede’s post: people are working on changing things so that future WoA Snapdragon laptops can boot Linux with ACPI only, without needing Device Tree. If that lands, it would wipe out much of the current pain, which is creating, testing and upstreaming a separate Device Tree for every Snapdragon X/X2 model.
For now the series sits as an RFC on the kernel mailing list, and it remains to be seen what shape it takes toward eventual mainline inclusion. If you run a Snapdragon laptop on Linux or follow Arm kernel support closely, this is worth watching. For context on where Arm is heading on Linux, read our article on running agentic AI workloads on Arm with Ubuntu.
Source
Phoronix: DeviceTree-ACPI Hybrid Mode Proposed For Improving Linux Support On Snapdragon Laptops