Google Plumbing The Linux Support For Privacy Screens On Intel Laptops

A number of recent laptops have begun appearing that offer support for built-in privacy screens with the press of a button. These privacy screens reduce much of the visible light when viewed at angles to try to block out the screen contents from anyone that may be sitting besides the user. Linux has finally begun seeing this support prepared.

As I wrote about last month as material that ended up being merged for Linux 5.4, there is now support for Lenovo PrivacyGuard as found on newer ThinkPad laptops to reduce their vertical/horizontal viewing angles when desired. That implementation was done as part of the ThinkPad ACPI Linux kernel driver.

Google engineers are now coming to the table with a wider solution -- at least for those laptops that are compatible with ACPI specifications where there is now a defined interface for toggling the functionality. Google's Rajat Jain is proposing a new DRM property for connectors so user-space can see the "privacy-screen" property and be able to check the status or toggle accordingly. The current DRM privacy-screen code proposed by Rajat checks for the relevant ACPI data and controlling it via the methods.

With the Google code, this is wired up just for the Intel display ports. Presumably Google is working on this privacy screen support for the capability in Chromebooks. At the moment there doesn't appear to be any Chromebooks with this privacy screen functionality built-in so most likely is for future devices.

The proposed DRM privacy-screen property can be found via this mailing list post.