Kernel Log - Coming in 3.6 (Part 4): Drivers
by Thorsten Leemhuis
Developers have improved support for new Apple MacBooks laptops. The Radeon driver now supports PCIe 2.0 and the kernel includes a driver for the Cinergy T Stick Black DVB-T receiver.
The kernel developers have merged a range of additions and bug fixes into Linux 3.6 aimed at improving support for Apple MacBook laptops released in July (such as the MacBook Pro Retina). These include one change which fixes a known boot problem. There have also been changes to the graphics drivers to initialise the graphics hardware on the latest MacBooks correctly. There are also new functions which are supposed to make it possible to turn the second graphics chip on newer Macs on and off with the platform driver apple-gmux (1, 2). Tests by The H's associates at c't Magazine in Germany using Linux 3.6-rc3 on a MacBook Pro with Retina display found, however, that enabling the GeForce graphics chip did not work and that the graphics hardware was not correctly initialised on booting. In contrast, Linux 3.5 did start with the help of a few tricks. Not all of the additions required for the new MacBooks have yet found their way into Linux. A patch for supporting the Bluetooth chip will not be merged into the kernel before Linux 3.7.
- The Radeon graphics driver now activates the fastest PCIe 2.0 transfer modes where these are supported by the hardware. Developers have also significantly improved source code documentation (1, 2 and others).
- There have been few changes to the nouveau driver for NVIDIA graphics cores as one of the main developers has been hard at work preparing a major revision which could find its way into Linux 3.7.
- Intel developers have significantly extended the list of Haswell graphics cores supported by the i915 graphics driver, as a result of which it now supports 37 members of this processor family which Intel appears to be planning on releasing over the next year.
- The audio drivers also now support Intel's Haswell processors and associated Lynx Point platform controller hubs (PCHs) (1, 2)
- Code for supporting Realtek's RTL2832 DVB-T demodulator, used in a number of different DVB-T receivers, has been merged into the media subsystem with its the DVB and V4L drivers. The code is used by additions to the dvb-usb-rtl28xxu driver, which consequently now supports Terratec's Cinergy T Stick Black.
Last Sunday, Linus Torvalds released the sixth pre-release version of Linux 3.6. He has asked users and developers to give this release candidate a thorough testing, as he says he would like to release the final version of Linux 3.6 "soonish".
- With the first half of a major restructuring of the EDAC (error detection and correction) subsystem having been merged into Linux 3.5, the second half has now been incorporated into Linux 3.6 (1, 2, 3, 4 and others).
- A driver for Lenovo's ThinkPad USB keyboard with trackpoint has been merged into the input subsystem.
- The multitouch driver now supports the HID protocol for Windows 8 multitouch devices.
- The work-in-progress drivers in the staging area have been joined by a 4 MB driver for an MMC-mounted Wi-Fi chip from CSR.
- The links in the Minor Gems section on the following page lead to many other changes aimed at improving Linux hardware support. These include a laptop driver for the Lenovo IdeaPad Z570 merged into Linux 3.6 and support for Samsung's R40 and R41 laptops. A large number of patches which extend the list of hardware for which the kernel automatically employs specific tweaks have also been merged into the kernel. As a result Linux should now be able to correctly configure the touchpads on some Dell Inspiron models and the audio hardware on ASUS' K53E and U41SV and Acer's 1810TZ and AOD260 laptops. The links on the following pages provide details of these and other tweaks.