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As previously reported, the kernel developers have, at the urging of Linus Torvalds, included the kernel code for the Nouveau driver for GeForce graphics cores (GPUs/Graphics Processing Units) into the Linux kernel's staging area. Version 2.6.33 of the kernel will, therefore, also offer Kernel-based Mode Setting (KMS) for many older as well as modern NVIDIA graphics chips; KMS has so far only been available with AMD/ATI and Intel GPUs. It allows flicker-free start-ups, faster switching between X Server and text console, and more reliable graphics hardware reinitialisation when waking from system sleep states. Based on the new kernel code, the yet unreleased Nouveau driver for is capable of dual screen operation via RandR and offers Xvideo acceleration for recent GeForce models – these two features are not available with the "nv" (full name "xf86-video-nv") driver many distributions configure for NVIDIA hardware. 3D acceleration, however, has not been mastered by either of the drivers – while it is currently under construction for Nouveau, in this reverse engineered driver it is still considered very experimental. The Noveau 3D support was previewed recently and worked well with Compiz and Extreme Tuxracer, but did not activate the graphic cards fan control.

The kernel's DRM (Direct Rendering Manager), which is used by the KMS drivers, and the Intel drivers based on it, will, from now on, offer an interface that improves the way graphics drivers synchronise the display of new screen content when flipping pages. This is to reduce or avoid "tearing", a type of image distortion which can be a particular nuisance when rendering video output. To make kernel-side "Page Flipping Support" available, the developers had to extend the DRI2 protocol. As a result, the technology will only be functional with Mesa 7.8, X Server 1.9 and with version 2.11 of the Intel graphics driver for, which is still in development. When combined with the "drmmode overlay support" feature first integrated in the KMS driver for Intel GPUs with Linux 2.6.33, the lastest version of the Intel graphics drivers for now supports video overlays. The developers have also included numerous improvements for Ironlake graphics cores, which are used in Westmere CPUs such as the series i3 and i5 dual core processors introduced at the beginning of the year.


This article provides an overview of the most important changes of Linux version 2.6.33. More detailed information can be found in the Kernel Log's of the "Coming in 2.6.33" mini series, released over the past few weeks on The H Open, which form the basis of this article.

  1. Networking
  2. Storage
  3. Graphics
  4. Architecture and virtualisation
  5. Drivers

In these articles, you will find the main sections that make up this article and an "In Brief" section which details important changes. There is also the "Minor gems" section which lists the many other changes not mentioned in the main article but which, for many users, are still of great significance.

For example, in the article on Drivers, "Minor gems" lists the numerous patches to support the video hardware on different PCs, notebooks and motherboards, and lists the changes to the V4L/DVB subsystem, which includes the addition of product names for TV hardware that the Linux kernel now recognises.

The kernel's DRM and KMS code for Radeon graphics chips now allows monitors to be controlled via DisplayPort (1, 2) and eDP (embedded DisplayPort); audio output via HDMI is now also possible. Another new inclusion is the IRQ support for r6xx and r7xx GPUs, which allows monitor change overs to be detected without repeated polling and is a prerequisite for the previously mentioned page flipping support for Radeon cards – however, the whole set-up will only work when combined with a firmware update. The developers also made many minor corrections and improvements to the Radeon KMS driver. As a result, the code has now matured to a degree that has allowed the developers to remove it from the staging area, which is intended for incomplete and low quality drivers, and indicate in their commit comment that the driver is now stable enough to be used in the Linux distributions. Meanwhile, back in the staging area, another new addition to the kernel is the vmwgfx KMS driver for virtual "SVGA2" graphics hardware, which is visible to guest systems in some of the VMWare hypervisors.

Next: Trimming, DRBD, Block Layer, Virtualisation and Tracing

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