Kernel Log: Linux 2.6.27 Released - The H Open: News and Features

In association with heise online

Many new and improved drivers

Which of the drivers were changed Information about the changes to individual Linux kernel files can be found through the Git web frontend at Kernel.org – this, for example, allows users to find out whether there have been changes to the drivers used on their own systems. To do this, however, users need to know where in the Linux kernel's source code tree the driver files are located. For the heavily modular distribution kernels the modinfo program is often helpful when searching: [VERBATIM0] If a compiled module is, for example, located at [...]/kernel/drivers/net/e100.ko, its source code in the Linux source code archive can usually be found in a file with a similar name in the drivers/net/ directory – for example e100.c for the e100 driver for Intel 100 MBit networking hardware. Other modules like the e1000 driver for Intel's PCI Gigabit LAN chips, on the other hand, have a whole directory to themselves. If the approximate location of the driver source code is known, users can navigate to the respective source code files in the tree view of the Git web interface and can then retrieve an overview of the latest file or directory changes via the history link. In the network driver directory, changes to the driver code of e100 (drivers/net/e100.c) and e1000 (drivers/net/e1000/), for example, can be displayed and examined this way.

Apart from the previously mentioned improvements to the Wi-Fi support there are also a vast number of new and improved drivers. Torvalds and his co-developers for example integrated a revised version of the gspca webcam driver collection which was mostly developed by reverse engineering (for example 1, 2, 3). The collection is suitable for cameras by a large variety of vendors – including numerous models by Aiptek, Creative, Logitech or Philips. Combined with its uvcvideo USB video driver integrated into Linux 2.6.26, just before the development cycle was closed, the Linux kernel will from now on support many of the popular webcams by default; previously, Linux users had to manually install the two drivers.

Very shortly before the merge window of Linux 2.6.27 was closed, Linus Torvalds, in a surprise move, integrated the mISDN (modular ISDN) framework into the freshly released kernel version (1, 2, 3, 4, 5, 6). This finally adds a much improved, modular ISDN driver designed for modern applications like phone system software to the kernel, and has been in development for several years. It predominantly handles the HFC chips made by Cologne Chip AG, which can be found on a range of passive ISDN cards and are often used for directly connecting ISDN phones. Asterisk also accesses the mISDN services using an mISDN specific API.

With 2.6.27, the kernel's audio drivers maintained by the Alsa Project (Advanced Linux Sound Architecture) have approximately reached the level of version 1.0.17 of the Alsa driver. Among this version's improvements are, for example, a driver for the Asus Xonar D1, a major overhaul of the snd-azt3328 driver, support for the ASUS Eeepc P90* audio hardware as well as numerous new ASoC (ALSA System on Chip) drivers.

As in almost every new kernel or Alsa driver version, the developers also extended the whitelists for the automatic application of hardware specific workarounds, allowing drivers to automatically perform the special audio codec tasks required for many PCs, notebooks and mainboards on more hardware (for example 1, 2). Linux users whose audio hardware will only work after they manually activate a workaround via module parameters when loading the sound driver should, therefore, send this information to the Alsa developers with details about their hardware. The developers can subsequently extend the whitelists. In the long run, users don't just benefit themselves but also do their fellow hardware owners a big favour, as their hardware will then also simply work without requiring them to put effort into manually trying out and configuring the various workarounds.

For the Atheros AR8121, AR8113 and AR8114 Gigabit LAN chips present particularly in the latest Asus netbooks, notebooks and mainboards, the kernel developers included the atl1e driver. In addition, a large patch provides support for the BCM57711 and BCM57711E LAN chips by Broadcom in the bnx2x driver. The e1000 driver no longer handles Intel PCIe Gigabit chips – these are now exclusively controlled by the newer e1000e driver which can now also address Intel's 82576 Gigabit NIC chip.

During the development of 2.6.27, problems were found with the e1000e driver; an unknown process was overwriting the non volatile memory (NVM) of the network interface, rendering it unusable. Modifications were made in a driver patch by Intel developers, which were refined by the kernel hackers (1, 2, 3, 4, 5, 6). The patch works by ensuring write protection is enabled on the non volatile memory, bypassing the damage done when some as yet unknown process or mechanism overwrites that area of memory. Developers are still investigating the underlying cause.

Major changes to the fujitsu-laptop driver now provide support for more Fujitsu-Siemens notebooks than before and improve the driver's interaction with userspace applications to control display brightness. The new divers compal-laptop and hp-wmi allow users to take advantage of some of the vendor specific features offered by Compal and HP notebooks; for example, both drivers forward events when users operate a switch or function key to enable or disable a wireless connection. Also significant for notebooks is the new sdricoh_cs driver which addresses the Ricoh Bay1 MM and SD card controller.

Next: new drivers for all, more improvements to the infrastructure

« previous 1 2 3 4 5 6 7 8 9 next »