Using hardware overlays for composing the display contents can provide significant power savings. However today's users are a demanding bunch, so the system must guarantee that display contents composed from multiple hardware overlays update in an atomic fashion. What challenges does that pose for the display driver, and what kind of changes are required for the DRM modesetting API?
Ville will start with trying to untangle the maze of terms like "atomic page flip" and "atomic mode setting".
Going on, the talk will includea short introduction to typical display controller hardware. Listing the relevant hardware components and the software abstractions we use to handle them.
There will a be short section on mode setting, and more specifically why both mode setting and atomic updates play a role in the current design.
Then we go through the atomic display updates, what is that we want to achieve, and what make is so difficult with current hardware.
Finally Ville will describe the new kernel APIs, and go through some of the design decisions leading to them.
Speakers: Ville Syrjala