Linux 6.7 Adds Support For Intel Meteor Lake Workload Type Hints

All of the power management related updates have been merged for the in-development Linux 6.7 kernel.

When it comes to the power management changes for Linux 6.7, there aren't any big shiny features for AMD or Intel this round. But there is a number of Arm SoCs now with new power management support. The Qualcomm SoCs now with CPU frequency scaling driver support include the Snapdragon 670 (SDM670), Snapdragon X75 5G modem (sdx75), and the Snapdragon 8 Gen 3 (sm8650). There is also support for the Qualcomm Immersive Home 3210 Platform (ipq5332), Qualcomm IPQ6018 802.11ax (ipq6018), Qualcomm Networking Pro 820 Platform (ipq9574), and Qualcomm Snapdragon 210 (msm8909) CPUFreq support.

Meanwhile the Rockchip RK3568 and RK3588 are now supported in their respective Devfreq driver.

Aside from those new SoC additions, most of the other power management changes for Linux 6.7 involve fixes and other low-level improvements. All the power management details here.

When it comes to the ACPI changes for Linux 6.7, it's mainly fixes.

The third pull request this week from Rafael Wysocki was the thermal control updates. Besides new Arm SoCs added there, of interest with this pull are Intel int340x thermal driver improvements. The Intel int340x driver now has power floor notification support, a rework to updating trip points in the driver, and workload hints support. Arrow Lake S PCI IDs are also added to the int340x driver.

The Intel int340x workload type hint support is interesting. Prior to Meteor Lake, user-space on Intel platforms can pass a "workload type" request to the firmware for optimizing power usage based on the specified workload type as well as the ability to implement its own heuristics. But with the forthcoming Meteor Lake platforms, the firmware can predict workload types without needing any user-space input.

With the new workload type interface of the Intel int340x driver in Linux 6.7+, the predicted workload hint is now exposed via sysfs for user-space. The driver also adds a new "workload_type_enable" sysfs attribute for toggling the workload type hints from the firmware.

The driver documentation notes that the predicted workload type values with Meteor Lake include idle, battery life, sustained power, bursty operation, and unknown.