DRM Improvements Coming Up For Linux 3.2 Kernel
The Linux 3.1 kernel should be released any day now after going through nine test releases, which will be followed by the opening of the Linux 3.2 kernel merge window. Here's some of the DRM improvements to look forward to in this next major kernel release.
With Kernel.org still being restored, David Airlie's DRM repository is temporarily hosted in its alternate location at git://people.freedesktop.org/~airlied/linux.git. Listed below is a portion of the Direct Rendering Manager changes that are part of his drm-core-next branch and being queued up for pulling into Linux 3.2.
- Allow PCI Express 2.0 (PCI-E Gen2) support for Northern Islands and Cayman (Radeon HD 6000 series) GPUs. Evergreen (Radeon HD 5000 series) support was previously available. This PCI-E 2.0 support was earlier introduced, but not enabled by default due to a driver bug that was exposed when enabling this support. This can allow for some potential speed increases.
- After a number of changes (some non-backwards-compatible ioctl changes and other work as VMware overhauls their Linux driver), the "vmwgfx" DRM driver that's used by guests of the VMware virtualization platform for GPU hardware acceleration, is leaving the Linux kernel staging area. With this driver leaving the staging area, its interfaces should now be stable and we'll hopefully see the VMware DRM driver enabled by default and found for use within more Linux distributions. There's also the VMware Gallium3D component in mainline Mesa.
- The Samsung Exynos 4210 DRM driver has been merged! This is the first DRM graphics driver for an ARM SoC being merged to the mainline Linux kernel. (The Texas Instruments DRM driver has yet to be pulled.) While the Exynos driver does handle KMS and memory management, this isn't a perfect driver as there aren't the bits for 3D acceleration (as there's no open-source Samsung Exynos user-space driver) and HDMI support is still lacking, but said to be coming. Regardless, kudos to Samsung for this work and managing to get this driver pulled. The Exynos 4210 is used by the Samsung Galaxy S II, Linaro's Origen development board, and a few other mobile devices.
- The Nouveau driver for Linux 3.2 should have DisplayPort improvements, backlight improvements, initial NV3x/NVCx (Fermi) memory timing support, and other miscellaneous work. There's also a few improvements to conserve power with Nouveau, plus NV40-specific re-clocking routines, but there isn't any major power management enhancements, fan management, or Fermi (GeForce 400/500) re-clocking support queued for the Linux 3.2 kernel.
- The Intel DRM driver has cleaned-up semaphore logic, initial ELD (EDID-Like Data) support, and other work that should benefit Sandy Bridge and Ivy Bridge hardware. The EDID-Like Data is for Eagle Lake, Iron Lake, Sandy Bridge, and Ivy Bridge hardware. ELD is used by the HDMI/DisplayPort audio driver to describe the capabilities of the attached monitor.
When the Linux 3.2 kernel merge window opens, there will be more information about the DRM graphics changes (along with benchmarks) and the improvements elsewhere in the Linux kernel.