KERNEL NEWS ZACK’S KERNEL NEWS

added an entry to the MAINTAINERS file New Complete git Dave’s final result goes all the way up listing himself as the official maintainer. Repository to v2.4, the point at which Linus started Darrick J. Wong wrote and submitted Peter Stahlir asked whether anyone had using BitKeeper. Git repositories cover- a driver to report the voltage, tempera- put together a complete git tree of the ing 2.4 to the present already exist, so ture, and fan sensor readings for the kernel, from version 0.01 to the present. Dave’s work just completes the history ADT7473 monitor chip. Periodically, this topic arises, and Linus back to the beginning. Steve Hardy wrote a driver to support Torvalds recently asked people to try to Dave published a 2G repository that the Burr-Brown/Texas Instruments do it. This time, Dave Jones said he’d includes more than a thousand commits, ADS7828 12-bit, 8-channel A/D con- been working on it and was trying to almost half of which have changelog en- verter used to monitor voltage on some split the repository into as many sepa- tries associated with them: git://git. off-the-shelf processors. rate patches as possible, rather than kernel.org/pub/ scm/ / kernel/ git/ Andrzej Zaborowski submitted the making each official version a single davej/history.git OMAP1 PWL-based LCD backlight driver mega-patch. Dave said he was trying to Also, the repository includes the full his- for inclusion in the main tree; the driver include every -pre, -test, and -rc patch as tory, including all forks for stable/develop- had been living for a while in the OMAP a separate commit. ment trees and any other experimental tree, and the time seemed right to get it Also, Dave was attempting to include trees Linus introduced along the way. Un- into the mainline kernel. the actual changelogs for as many of the fortunately, it appears that several kernel David Sterba felt the time had come to commits as possible, something no one releases have been lost forever. migrate the 3G UMTS PCMCIA card wire- else has tried because of the horrifying Also, now that Dave has published his less driver from Andrew Morton’s -mm size of the task. Remember that back work, more data continues to be added kernel into the mainline tree, so he sub- then, “changelog” might mean a snippet to the archive and errors are being cor- mitted the patch. As it turned out, several of email in the middle of a long thread. rected. The true record might not be folks had some technical issues that Along the way, whenever Dave encoun- complete for some time, and revisions hadn’t come up when the code only lived tered people working on similar projects, will continue to be added as more infor- in the -mm tree. and others he grabbed any changelogs he needed to mation is discovered. offered technical criticisms, and David fill in the gaps. promptly submitted an updated patch ad- New Drivers dressing these concerns. At this point, Jiri The Adrian McMenamin wrote code to sup- Kosina approved the patch and passed it mailing list com- port the CD-ROM drive on the SEGA up to Andrew, who also approved it and prises the core of Dreamcast. Also, his driver implements passed it up to . Linux development the proprietary Sega Packet Interface and Thomas Bogendörfer submitted a activities. Traffic vol- supports the proprietary Giga Disk ROM serial driver supporting SC2681/SC2691 umes are immense, disc format (known as the GD-ROM UARTs, saying that older SNI RM400 often reaching ten format). Several folks offered technical systems relied on those chips for their thousand messages feedback, and Adrian quickly submitted on-board serial ports. in a given week, and updated patches based on their criti- Harald Welte picked up the threads of a keeping up to date cisms. After a while, criticisms ended project started years ago by Thomas Klef- with the entire scope of development and the updated patch seems likely to fel – an MMC/SD driver for the Samsung is a virtually impossible task for one go into the main tree. S3C24xx SD/MMC controller. Thomas person. One of the few brave souls to Jochen Friedrich coded up support had abandoned the project when he’d take on this task is Zack Brown. for the watchdog timer on PowerQUICC run out of time to work on it but gave Our regular monthly column keeps you abreast of the latest discussions hardware, and this watchdog can be Harald permission to take it over. Harald and decisions, selected and summa- activated by the bootloader. After activa- brought the driver up to compliance with rized by Zack. Zack has been publish- tion, it cannot be disabled again but the current SD/MMC API and made it ing a weekly online digest, the Kernel must be reset periodically to prevent an mergeable with the mainline kernel tree. Traffic news letter for over five years automatic reboot. No real criticism was The plan was that once the driver was now. Even reading Kernel Traffic alone directed toward the patch, so it looks successfully merged, Harald and Thomas can be a time consuming task. like it’s going in. would be co-maintainers. Pierre Ossman Linux Magazine now provides you Alex Dubov has submitted a GPLed took issue with the excess of debugging with the quintessence of Linux Kernel patch supporting Sony’s secret, proprie- code, among other things, in Harald’s activities, straight from the horse’s tary protocol for their MemoryStick card, patch. Harald said he’d update the patch mouth. found in many Sony products. Alex also and resubmit it.

14 ISSUE 88

014-015_kernel.indd 14 17.01.2008 15:04:54 Uhr KERNEL NEWS

Finding someone to maintain the code Removing Old Stuff Pavel’s response was that waking up regularly was the real goal. In response Dmitri Vorobiev removed the documen- on network traffic is a distant goal, but to Bartlomiej’s submission, Borislav tation/mips/GT64120.README file from he did suggest that perhaps something Petkov volunteered and started talking to the 2.6 tree because it really was 2.4-spe- could be done at the router end so the Andrew Morton about driver updates. cific and referred to files and directories sleeping system only gets “interesting” that didn’t exist. The document dis- packets. cussed the GT-64120 system controller Auto-Suspend and -Awaken After this objection, and several others chip, in common use on many MIPS Pavel Machek is in the early stages of like it, a bunch of people started adding motherboards. writing code that allows suspended sys- feedback on how to implement various tems to wake up on their own under cer- features. Someone even suggested that IDE-CD Driver Rewrite tain conditions. Pavel envisions laptops the Linux folks might be able to work Bartlomiej Zolnierkiewicz reworked the waking up at a certain time of morning with the hardware vendors on specs for ide-cd driver and submitted his changes. with an MP3 player or if certain network hardware that would support features. One big reason for the rewrite was that traffic comes in. Still, there are many Overall, people – including Oliver Neu- ide-cd has not had a maintainer for quite obstacles, and Pavel points out that the kum, Ingo Molnar, and H. Peter – are in- some time, so any new fixes have been code he’s written doesn’t even work on terested in Pavel’s project. The project is grafted into the existing code, resulting his own systems yet. Getting something still new and has many obstacles, special in a code base that has become uglier – anything – working for this feature cases, and an array of hardware that will and harder to debug or maintain. seems to be Pavel’s main goal for now, be iffy to support, but it will be fun to Bartlomiej’s work cleans this up. then more stuff can be added later to watch how the project develops. Another reason for the rewrite was to support different hardware and software allow developers working in other areas, configurations. INFO such as libata ATAPI, to identify the H. Peter Anvin pointed out that wak- [1] Kernelnewbies Japan: special cases for devices they want to ing up on network traffic would result http:// lists. kernelnewbies. org/ support in their code. Bartlomiej’s in the system waking up on broadcast mailman/ listinfo/ jp-kernelnewbies rewrite was just a stopgap, however. packets, which happens all the time. 16 PROCESSOR CORES • Quad AMD Opteron 8000 • 2U rackmount • Serial ATA or SAS RAID 16 cores from £3,758 + VAT • Up to 64GB of memory 8 cores from £2,573 + VAT • Linux OS Prices correct as of 16-10-2007

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014-015_kernel.indd 15 17.01.2008 15:05:00 Uhr