New graphics and notebook drivers, staging area, statistics

Medium Tux KL

Graphics and notebooks

A great number of changes in 2.6.30 improve the emerging GEM and KMS technologies that have so far only been used in Intel GPUs. A patch of almost 650Â Kbytes in size integrates the microcode for the Radeon R600 and R700 GPUs used in the Radeon-HD models of the 2000, 3000, and 4000 series. The newly integrated support of these GPUs in the kernel's Direct Rendering Manager (DRM) uses this microcode to provide recent graphics drivers with Xvideo functionality and 2D acceleration. Also newly supported in the DRM is the chip-set for RS600 motherboards. The Intel drivers are now capable of TV output on some of the boards and can handle the G33 and G41 chip-sets.

New in Linux 2.6.30 is the dell-wmi driver, although it currently only forwards hotkey events in Dell notebooks. The sony-laptop and thinkpad-acpi have undergone major restructuring â the former now supports more notebook models and event types than before, whilst the latter offers improved brightness control for ThinkPads.

Staging

A whole host of changes was introduced in the staging area. The staging area is a special kernel section used for collecting and improving drivers which don't (yet) match the kernel developers' quality standards â some distributions don't even include the staging drivers for this reason.

The Git pull request lists all the major changes â all of the Comedi framework drivers, for instance, have now been included. Another first timer is the rt3070 driver for recent RaLink Wi-Fi chipsets. The staging area now also includes a file system, POHMELFS (Parallel Optimized Host Message Exchange Layered File System). Also new to the staging area is DST (Distributed (Network) Storage) by the same developer â find details about this in the articles "Distributed storage" and "CRFS and POHMELFS" were released on LWN.net some time back, as well as on the POHMELFS and DST home pages.

Information from the source code management system

Many of the links in this article point to the relevant commits in the web frontend of Linus Torvalds' Git source code management system for Linux, because these commits tend to contain a lot more information about the respective changes. The commit comment in the mid section of the web page displayed by the Git web front end is often a particularly helpful source of further information. This is where the author of a patch usually describes the background and intended effects of the changes.

The bottom section of the Git web front end lists the files that are affected by the patch. The "diff" link behind each file name shows how the patch modifies the respective file; if you want to view the complete patch in its raw form, click on the commitdiff link. Even if you don't have any programming skills the patches are often a good source of information, because they also contain changes to the documentation and comments within the code.

Dates and figures pertaining to the most recent Linux kernel versions

Linux version	number of filesÂ¹	lines of source codeÂ²	development time	number of commitsÂ³	diffstatâ´
2.6.25	23810	9232484 (8396250)	83Â days	12243	9738Â filesÂ changed, Â 777371Â insertions(+), Â 404514Â deletions(-)
2.6.26	24270	9411724 (8535933)	88Â days	9941	8676Â filesÂ changed, Â 595393Â insertions(+), Â 416143Â deletions(-)
2.6.27	24354	9709868 (8690888)	88Â days	10628	15127Â filesÂ changed, Â 1131171Â insertions(+), Â 912939Â deletions(-)
2.6.28	25255	10195507 (9128690)	76Â days	9048	11090Â filesÂ changed, Â 975689Â insertions(+), Â 490047Â deletions(-)
2.6.29	26668	11010647 (9871260)	89Â days	11718	10933Â filesÂ changed, Â 1347290Â insertions(+), Â 532055Â deletions(-)
2.6.30	27879	11637173 (10419567)	78 days	11989	10259Â filesÂ changed, Â 1086737Â insertions(+), Â 460298Â deletions(-)
Â¹Â find . -type f -not -regex '\./\.git/.' \| wc -l Â²Â find . -type f -not -regex '\./\.git.' \| xargs cat \| wc -l (find . -name .[hcS] -not -regex '\./\.git.' \| xargs cat \| wc -l) Â³Â git-log --no-merges --pretty=oneline v2.6.(x-1)..v2.6.(x) \| wc -l â´Â git diff --shortstat v2.6.(x-1)..v2.6.(x)