Privacy-Screen DRM API With Intel Support Ready Now That GNOME Is Prepared To Use It

Over the past two years we have seen work around bringing up privacy screen support on Linux whereby an increasing number of laptops can reduce the amount of visible light when viewed at wide angles to try to block the screen contents from anyone potentially snooping at the screen. Ready to go now is the DRM/KMS user-space interface and the Intel graphics driver support now that there is a user-space "client" ready.

In recent times there has been Lenovo PrivacyGuard work for Linux and Dell privacy support. As part of enhancing the Lenovo ThinkPad support there has also been a patch series by Hans de Goede working on the necessary changes from the DRM/KMS driver side, coming up with a common user-space interface via KMS properties for indicating it, and getting it implemented for the Intel i915 driver.

Hans this week sent out the latest version of the patches that is just re-based against the latest Direct Rendering Manager code state. It's the first update on it since April but now believed to be ready since there is consensus among upstream developers around the privacy-related code. But more pressing is GNOME has user-space code ready to go that can make use of these new KMS properties.

There are GNOME patches pending to the relevant components for making use of the privacy-screen capabilities, providing an on-screen display notification when enabled/disabled, allowing the privacy screen to be toggled via the GNOME Control Panel, and user handling around the feature.

With a viable user-space client available that makes use of the new kernel code, it should now be on a trajectory for merging. More details for those interested in this privacy screen topic via this patch series.

It's too late for the 5.15 kernel but perhaps we'll see it now set for 5.16. For distributions / kernel builders, it does introduce some new complications in that the i915 driver loading is now deferred until after the ThinkPad ACPI driver is loaded on relevant ThinkPads with privacy screens. Thus the thinkpad_acpi driver will likely need to be pulled into the initrd images of distribution kernel builds if not already done so.