| 1) Support dma-buf memory management. |
| |
| In order to zero-copy import camera images into the 3D or display |
| pipelines, we need to export our buffers through dma-buf so that the |
| vc4 driver can import them. This may involve bringing in the VCSM |
| driver (which allows long-term management of regions of memory in the |
| space that the VPU reserved and Linux otherwise doesn't have access |
| to), or building some new protocol that allows VCSM-style management |
| of Linux's CMA memory. |
| |
| 2) Avoid extra copies for padding of images. |
| |
| We expose V4L2_PIX_FMT_* formats that have a specified stride/height |
| padding in the V4L2 spec, but that padding doesn't match what the |
| hardware can do. If we exposed the native padding requirements |
| through the V4L2 "multiplanar" formats, the firmware would have one |
| less copy it needed to do. |
