Next-Gen DMABUF: How To Efficiently Play Back Video on Embedded - L. Stach, Pengutronix скачать в хорошем качестве

Next-Gen DMABUF: How To Efficiently Play Back Video on Embedded - L. Stach, Pengutronix

The current generation of embedded SoCs contain diverse loosely coupled hardware accelerator modules that need to cooperate in order to meet the needs of common use cases, like video playback with fluid 3D rendered user interfaces. Userspace is able to coordinate this work and pass around the used memory resources using opaque handles, by utilizing the recently introduced DMABUF kernel framework. This works well as long as the hardware modules have equal constraints on the memory layout. When requirements differ, for example if, as often the case on embedded systems, only parts of the pipeline support scather-gather DMA, the current DMABUF implementation reaches its limits. We propose in-kernel extensions to the existing DMABUF framework which allow to cover those cases without userspace-visible impact. We will walk through the necessary steps using the example of a simple video pipeline http://events.linuxfoundation.org/eve...