Support for MultiHead configurations of XFree86 has been designed into the DRI. However, full implementations of multihead support have not be done. There are many variations on how multihead can be supported on XFree86. This section describes what's possible, and where more work is needed.
Many of the challenges with supporting basic multiple adapter multihead reside in getting basic 2D initialization for all heads. Some XFree86 drivers work better than others in this area. The focus from a DRI perspective, is to make sure 3D works if 2D does. This has not been done for many of the DRI drivers, but is something that can be addressed at the driver level. When attempting to support basic multihead functionality within a driver, there are multiple levels of increasing complexity that should be addressed:
- 2D working on all heads, 3D on none
- 2D working on all heads, 3D working on a single head
- 2D working on all heads, 3D working on all heads For many configurations, the biggest development challenge for the last step may be getting AGPGART support going with multiple heads. It's possible to defer this by working with drivers that don't require this support (PCI-only).