David Airlie has announced on his blog that he and Alex Deucher have finally got support for DisplayPort-driven graphics cards and monitors working with the open-source ATI Linux driver stack. Not only is there user-space mode-setting support via the xf86-video-ati DDX driver, but the kernel mode-setting for this latest monitor interface is working too. David had been working on DisplayPort support some months ago, but today DisplayPort monitors are finally lighting up and working correctly with the latest ATI driver code.
To use the DisplayPort interface with the open-source ATI driver (using the binary-only Catalyst driver should already work with DisplayPort monitor for many months), checking out separate Git branches of xf86-video-ati and DRM code is currently required. Fortunately, however, this code should be merged into the mainline xf86-video-ati driver soon and it looks like the kernel side of this support will be merged into the Linux 2.6.33 kernel
. This support will also improve once R600 IRQ support emerges (coming very soon) and the code cleaned up to share some of the DisplayPort code with Intel's driver, which already supports this standard.
More details can be found on David Airlie's blog