Kernel Log: updated Radeon drivers, mdadm and ALSA
by Thorsten Leemhuis
A new version of the AMD driver from X.org improves support for modern Radeon graphics chips. An updated mdadm, initially only designed for developers, allows the RAID functions of modern Intel motherboard chip-sets to be used. After nine months, the ALSA project has published a new version.
AMD’s kernel and X.org developer Alex Deucher has published version 6.14.0 of driver package xf86-video-ati. It contains the X.org driver for Radeon graphics hardware, which provides much better support for the latest version of Radeon graphics chips. For example, it now not only controls the graphics kernel of the Fusion processors developed under codename "Ontario", but also the Northern Islands GPUs based on Radeon HD models 62xx to 68xx. With both of them, 2D acceleration via EXA now works, as does video acceleration with the antiquated Xv (Xvideo), but in both cases the driver remains dependant on Linux kernel 2.6.38, which is still under development and is expected to be released at the end of March or beginning of April. Its DRM driver with functions for KMS (kernel-based mode-setting) is required anyway for Northern Islands GPUs because the driver does not support UMS (user mode-setting) on these chips.
In combination with KMS in kernel 2.6.36 and later, the driver also supports EXA and Xv on Evergreen GPUs on Radeon HD 5,000 series models. The developers have considerably upgraded the man page in the new version. Along with kernel 2.6.38, the driver offers page-flipping support so that image updates are more precisely synchronised with the start of frame re-draw. For further information on this new technology in Linux 2.6.38, see the first part of the series "Coming in 2.6.38".
In combination with Mesa 7.10, 3D acceleration also reportedly works on Evergreen and Ontario GPUs. The code to control the GPUs’ 3D units on Radeon HD models 62xx to 68xx is already in the developer branch of Mesa 3D and will probably be part of Mesa 7.11, but a number of the distributions released in the next weeks and months will probably back port these changes.
RAID management tool
Neil Brown has published version 3.2 of software RAID configuration tool mdadm, although he does explicitly point out that this version is only intended for developers; you should not use it without studying the release email, which lists all of the major changes. For instance, the code to reshape arrays has been considerably restructured so that it now works well with externally managed metadata. In other words, mdadm now supports switches of RAID levels without data loss and can enlarge arrays with Intel's IMSM format, which is used by a lot of the RAID adapters in Intel chip-sets for desktop motherboards.
In the "Policy Framework", you can now make settings in mdadm.conf that affect the way mdadm behaves. In particular, this option is considered especially interesting when you want to add devices with the option "-I/--incremental" so that a device that has fallen out of the array will automatically be put back into it. For this purpose, mdadm now understands partition tables to a limited extent. Brown hopes that version 3.2.1 planned for the beginning of March will be suitable for general implementation.