NVIDIA Prepares The Linux Kernel For Future Laptops With EC-Driven Backlights

NVIDIA is contributing a new open-source driver to the upstream Linux kernel for dealing with upcoming laptops where the backlight controls are handled by the device's embedded controller (EC).

With Linux 5.16 later this year NVIDIA is ready with the "wmaa-backlight-wmi" driver for EC-based backlight controls for upcoming laptop/notebook computers.

This new driver is queued as part of the platform-drivers-x86 material in "for-next" ahead of Linux 5.16. The NVIDIA patch explains:

A number of upcoming notebook computer designs drive the internal display panel's backlight PWM through the Embedded Controller (EC). This EC-based backlight control can be plumbed through to an ACPI "WMAA" method interface, which in turn can be wrapped by WMI with the GUID handle 603E9613-EF25-4338-A3D0-C46177516DB7.

Add a new driver, aliased to the WMAA WMI GUID, to expose a sysfs backlight class driver to control backlight levels on systems with EC-driven backlights.

NVIDIA has been working on this ~200 lines of code WMAA Backlight driver for Linux since last year and is being maintained upstream by Daniel Dadap of the company.