Has AMD Finally Fixed Tearing With Its Linux Driver?

AMD put out a rare beta Linux driver this Monday and they have now just announced the release of the Catalyst 11.1 driver as their stable monthly update for Linux and Windows users. With this Catalyst driver, there is though one interesting but hidden feature that is sure to please many ATI/AMD Radeon Linux desktop users.

While the Catalyst 11.1 driver only officially mentions Red Hat Enterprise Linux 6.0 production support and Red Hat Enterprise Linux 5.6 "early look" support as the changes, but there is more. Hidden away within this driver is finally the code that will hopefully eliminate screen tearing for the proprietary Radeon/FirePro Linux driver. This tear-free vsync support is currently considered a "work in progress" but can be enabled manually. This support is designed to ensure a tear-free experience throughout the entire desktop across the spectrum of 2D, 3D, and video applications.

To enable this support in the Catalyst 11.1 driver (and in future releases until it's officially acknowledged as a feature by AMD and enabled by default), it is just a matter of running aticonfig --set-pcs-u32=DDX,EnableTearFreeDesktop,1 followed by restarting the X.Org Server. If you enable the support and then hit any issues or wish to disable the tear-free capability for whatever reason, it's just a matter of issuing aticonfig --del-pcs-key=DDX,EnableTearFreeDesktop.

Using this tear-free desktop though does require extra video memory, so those with limited amounts of VRAM may be stuck without this support. This tear-free support is also specific only to the Catalyst driver. There's separate work going on within the open-source ATI driver stack for KMS page-flipping, swap buffer waits, and other vblank work in efforts to reduce screen tearing but at the cost of performance.

As AMD hasn't officially acknowledged this feature yet to this public of the tear-free desktop or the method of enabling/disabling the support, as always, stop by the Phoronix Forums if you run into any problems.

Other fixes found in today's driver release include fixing the kernel module build against the Linux 2.6.37 kernel, X segmentation faults under different scenarios, fixing up display hot-plugging on SuSE Linux Enterprise Desktop, and reducing the driver's build size by about 15MB. Yes, this driver should work with the recently released Linux 2.6.37 kernel.