Every modern multimedia-oriented ARM SoC usually has a number of display controllers, to drive a screen or an LCD panel, and a GPU, to provide 3D acceleration. The Linux kernel framework of choice to support these controllers is the DRM subsystem.
This talk will walk through the DRM stack, the architecture of a DRM/KMS driver and the interaction between the display and GPU drivers. The presentation is based on the work we have done to develop a DRM driver for the Allwinner SoCs display controller with multiple outputs, such as parallel display interfaces, HDMI or MIPI-DSI. The work done to make the ARM Mali OpenGL driver work on top of a mainline DRM/KMS driver will also be detailed, as well as the more traditional, Mesa-based, solution used in a variety of other platforms.
Maxime Ripard, Free Electrons