Libdrm 2.4.48 features AMD Hawaii GPU support for the Radeon R9 290 series and other upcoming graphics processors on the latest GCN revision. Having Hawaii support also requires the latest Git version of the xf86-video-ati DDX and enabling the xorg.conf acceleration option, the latest Mesa Git, LLVM 3.4 SVN, and the Linux 3.13 kernel.
Newly supported in libdrm 2.4.48 is also Intel Broadwell graphics support, the 2014 successor to Haswell. Broadwell graphics are very exciting according to the developer comments and we look forward to its arrival in a few months. Intel Broadwell Linux GPU support also requires the Linux 3.13 kernel (though will be much better in Linux 3.14), the Mesa Git branch for Broadwell, and xf86-video-intel Git.
The only other change worth mentioning with the libdrm 2.4.48 release is support for the GPU reset status query ioctl for Intel hardware.
More details on the new DRM library release can be found via the dri-devel release announcement.