1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking Benchmarking Platform
Phoromatic Test Orchestration

DisplayLink Continues To Progress On Linux, But No 3D

Hardware

Published on 02 June 2011 05:51 PM EDT
Written by Michael Larabel in Hardware
Comment On This Article

It was back in May of 2009 that DisplayLink began providing open-source Linux support for their USB-interfaced graphics processors in the form of documentation and code. Shortly thereafter, frame-buffer and X.Org drivers for DisplayLink USB hardware arrived and it quickly matured. By early 2010 it was possible to produce interesting results with these USB graphics adapters doing things like driving nine monitors over USB from a single computer.

A number of features have been added in succeeding kernel releases over the past two years. Most recently, during the Linux 2.6.39 kernel development cycle, DRM support for USB devices was added making it now possible to write a Direct Rendering Manager driver for DisplayLink hardware and to hook into kernel mode-setting. The code for a DRM/KMS DisplayLink driver is not yet written, but will most likely appear at some point in the future.

One limitation of the DisplayLink Linux support that still remains, however, is the lack of 3D support. These low-power USB graphics adapters don't have a 3D engine. Under Windows, 3D on DisplayLink hardware is achieved by using the primary GPU on the system and then simply sending it out to the DisplayLink GPU so that it can be painted to that scan-out buffer. Something similar would need to be implemented under Linux so that there could be 3D support and even a composited desktop, but right now the infrastructure is lacking. This was a question recently asked on the DRI development mailing list.

This lack of infrastructure falls into the same boat of the Linux multi-GPU rendering being way behind, no AMD CrossFire / NVIDIA Scalable Link Interface support, NVIDIA Optimus for some hardware where only one GPU is connected to the output, and other technologies like LucidLogix Virtu.

Kernel changes and to the X.Org stack would be needed for this multi-GPU rendering to all play nicely. David Airlie previously experimented with a project he calls PRIME rendering for using one GPU to render and then displaying the contents on a display connected to another GPU, but it was just a proof of concept and is not being worked on at this point. As long as the graphics processor employed GEM memory management, it in theory could work with any graphics driver/GPU. Getting this work upstream is a huge feat and requires major re-architecting of the X Server and Linux drivers. With the Wayland Display Server, this will hopefully be much smoother.

Sadly, hitting these features under Linux will not be a short-term goal.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Articles & Reviews
  1. Sub-$20 802.11n USB WiFi Adapter That's Linux Friendly
  2. The Lenovo T450s Is Working Beautifully With Linux
  3. Linux 4.0 SSD EXT4 / Btrfs / XFS / F2FS Benchmarks
  4. Linux 4.0 Hard Drive Comparison With Six File-Systems
  5. Lenovo ThinkPad T450s Broadwell Preview
  6. How Open-Source Allowed Valve To Implement VULKAN Much Faster On The Source 2 Engine
Latest Linux News
  1. Features Thus Far For The Linux 4.1 Kernel
  2. Intel's Turbostat Adds Skylake Support In Linux 4.1
  3. Microsoft's Open-Source Group Merges Back Into The Company
  4. EXT4 In Linux 4.1 Adds File-System Level Encryption
  5. Open-Source Ardour 4.0 Audio Software Has Big Improvements
  6. Linux-Powered Endless Computer Raises $100k+ In A Few Days
  7. GCC 5.1 RC2 Arrives, GCC 5.1 Planned For Next Week
  8. F2FS For Linux 4.1 Has New Features & Fixes
  9. Phoronix Server Upgrade This Weekend: Dual Haswell Xeons, 96GB DDR4
  10. Google's Experimental QUIC Transport Protocol Is Showing Promise
Most Viewed News This Week
  1. Nouveau: NVIDIA's New Hardware Is "VERY Open-Source Unfriendly"
  2. Linux 4.0 Kernel Released
  3. Linux 4.1 Brings Many Potentially Risky x86/ASM Changes
  4. Microsoft Announces An LLVM-Based Compiler For .NET
  5. VirtualBox 5.0 Beta 2 Released
  6. KDBUS Is Taking A Lot Of Heat, Might Be Delayed From Mainline Linux Kernel
  7. Mozilla Start Drafting Plans To Deprecate Insecure HTTP
  8. LibreOffice 4.5 Bumped To Become LibreOffice 5.0