The merge window for the Linux 3.4 kernel will open up this month assuming the latest Linux 3.3 release plans work out. One of the features to look forward to out of Linux 3.4 will be the DRM driver support for Intel Medfield graphics.
It’s still tough to find Intel Medfield hardware out in the wild at the moment, but the low-power Intel hardware will be powering more smart-phones moving forward. Unfortunately, the Medfield platform relies upon PowerVR-derived graphics, similar to Intel’s notorious Poulsbo. Imagination Technologies doesn’t allow PowerVR licensees to provide open-source 3D graphics drivers, which has been handicapping Intel and other vendors. Imagination keeps the PowerVR intellectual property tightly closed.
The good news is that Intel is dropping PowerVR graphics in the future and that for the 3.4 kernel there will be at least basic DRM/KMS support for Medfield. Alan Cox has been adding Medfield support to his GMA500-Poulsbo DRM driver. This DRM driver doesn’t provide any graphics hardware acceleration nor feature-rich like the in-house Intel / Radeon / Nouveau DRM drivers. The open-source Poulsbo driver just provides a clean mode-setting experience and a slightly better experience than using the xf86-video-vesa DDX driver without kernel mode-setting.
To the DRI development list, Alan Cox sent over a set of 47 patches for the Poulsbo driver. This work is to be merged for the Linux 3.4 kernel. This set of 47 patches adds around 6,000 lines of new code to the opens-source “GMA500” driver. Most of this is the Medfield hardware enablement plus some clean-up work.
The Medfield enablement work wasn’t done single-handedly by Alan Cox like he’s done in the past with Poulsbo as his pet project, but by Kirill A. Shutemov, a fellow Intel OTC engineer. The current Medfield support is considered experimental.
The Medfield support covers kernel mode-setting, backlight control, and other basic functionality. But there remains no 2D/3D acceleration support. Though there may be some hope of seeing 2D acceleration in the future with 2D acceleration references in one “mdfld” struct and a code comment for “2D acceleration.”
Meanwhile, other Linux 3.4 kernel changes to look forward to include performance improvements to Intel’s main DRM driver (Sandy Bridge, Ivy Bridge), a DisplayLink KMS driver, more Android staging patches, hopefully Radeon HD 7000 series support, and a lot of other work to be talked about in the coming weeks.