AMD "Automatic Mode Transition" Comes For Lenovo ThinkPad Laptops With Linux 6.0

AMD Automatic Mode Transition (AMT) is a new feature wired up for Ryzen-powered ThinkPad laptops that is being introduced with the Linux 6.0 kernel.

Lenovo and AMD engineers recently posted the Linux patches for "Automatic Mode Transition" as a power/performance automatic handling option that at least initially seems just found on Lenovo ThinkPad laptops. I haven't been able to find much about AMD's Automatic Mode Transition (AMT) functionality but some indications are that it's specific/limited to Lenovo models, besides this AMT enablement just happening for the ThinkPad ACPI kernel driver.

AMD Automatic Mode Transition appears to be for dynamic firmware-based altering of the power/performance characteristics. It's tied into the ACPI Platform Profile support that when in the default "balanced" mode at boot, with Linux 6.0+ on supported ThinkPads the AMT will engage for dynamically adjusting the platform profile characteristics based on firmware-driven decisions.

Besides needing to be in the default "balanced" ACPI Platform Profile mode, on some AMD platforms the Fn + T combination can be used for toggling whether Automatic Mode Transitions are active. That is the way for those interested to toggle AMT functionality. Printed to dmesg on Linux 6.0+ ThinkPad systems will be a message whether AMT is enabling/disabling.

Coincidentally just last week I posted some benchmarks of the ACPI Platform Profile mode on the Ryzen 7 PRO 6850U with ThinkPad X13 Gen3. The performance mode can squeeze out some slight advantages at higher performance/thermal costs while the low-power mode really ramps things up for power-savings and leading in performance-per-Watt. I'll be testing this ThinkPad X13 Gen3 out with Linux 6.0 Git shortly to see if AMD AMT indeed works there and the impact of this little-documented AMD/Lenovo feature.

AMD and Lenovo continue working on Linux laptop support enhancements.

While the AMD AMT integration in Linux 6.0 is just for Lenovo with the ThinkPad ACPI driver, more broadly and for use across vendors, AMD recently began posting the AMD Platform Management Framework (PMF) driver. AMD PMF is much more encompassing than AMT and cross-vendor, starting with AMD Rembrandt SoCs. AMD PMF appears to be akin to Intel's Dynamic Platform and Thermal Framework (DPTF) in that it's a centralized framework based on sensors, hints, platform state, and hardware metrics for dynamically changing the performance/power behavior.

The AMD AMT support for ThinkPads was submitted as part of the platform-drivers-x86 updates sent in for the Linux 6.0 merge window. That pull also has more Microsoft Surface laptop support improvements, microphone mute LED handling in the ASUS WMI driver, Intel Primary-to-Sideband (P2SB) updates, and other small changes for benefiting Linux laptops and more.