So I took a crack at tear free rendering on radeon using using the WAIT_UNTIL register to stall rendering until the vline leaves the active part of the display. I’ve never really been one to notice tearing, so I can’t tell how well it works.
- Only implemented for EXA and textured video where the destination is the front buffer (no need to stall for offscreen rendering)
- For EXA, I pick the crtc based on who has a larger part of the desktop. Ideally we’d have separate pixmaps per crtc.
- For Xv, I pick the crtc based on which one more of the dest window (need to add XV_CRTC attribute for clone mode)