What is possible, however, is running a single DisplayLink adapter, or several with a Xinerama or multiseat configuration — just as long as you don’t expect to use your main GPU at the same time.

The single-display case is relatively easy to set up, and we’ll cover that here.

First, make sure you’re running kernel version 2.6.35 or later (Ubuntu 10.10 or later). For older kernel versions, you’ll need to update udlfb and run a modified fbdev X server (not covered in this post). On these kernel versions, when you plug in your DisplayLink-based USB graphics device, you should get a green screen. This means that at the driver built into the Linux kernel is happy, healthy, and talking to the device.

Second, if you are running Unity Desktop in Ubuntu 11.04 or later, you’ll need to switch back to Classic Mode so you’re running straight X. Here’s how on Ubuntu:

Click on the power button in the upper right corner (mine looks like a light switch) and choose the last option, System Settings. Search for Login Screen, Double-click to display, Choose Unlock and enter your password, Select Ubuntu Classic as default session.

Third, if you’re running kernel versions between 2.6.35 to 3.1, enable the fb_defio option of udlfb. To do this, create or edit a file like
/etc/modprobe.d/50-displaylink.conf

and add the single line

options udlfb fb_defio=1

And reboot (or run “sudo depmod -a” and unplug/replug your adapter). This will turn on defio (page fault change detection) support. This option is already enabled by default in kernels 3.2+.

Lastly, create an X config file called 60-plugable.conf (or similar) with the following contents and place it in /usr/share/X11/xorg.conf.d (on recent distros; on older distros, make this your xorg.conf):

 
Section "Device" 
  Identifier "uga" 
  driver "fbdev" 
  Option "fbdev" "/dev/fb0" 
  Option "ShadowFB" "off"
EndSection 
 
Section "Monitor" 
  Identifier "monitor" 
EndSection 
 
Section "Screen" 
  Identifier "screen" 
  Device "uga" 
  Monitor "monitor" 
EndSection 
 
Section "ServerLayout" 
  Identifier "default" 
  Screen 0 "screen" 0 0 
EndSection

Note: if your main GPU creates a /dev/fb0 even when the USB display is not attached, then your USB display is probably getting assigned to /dev/fb1. In that case, change /dev/fb0 in the “Device” section above to /dev/fb1

Now, on reboot, you should (hopefully!) see your login come up on your DisplayLink USB attached display!

This kind of simple setup is useful for:

• Testing or playing with your USB graphics adatper on Linux.
• Embedded systems with USB but no GPU.
• As a backup method when the main GPU or its driver isn’t available or working.
• Systems where a USB graphics adapter enables higher modes (up to 2048×1152) than the main GPU screen.

Please comment if you have any trouble with this single display case. See our past posts for additional information about the DisplayLink Linux kernel driver and some more involved setups.

The instructed here work on all Plugable USB 2.0 graphics adapters and Plugable USB 2.0 docking stations and thin clients (and should also generally work on all DisplayLink based products).

So we’re excited to launch a hub with a lots of expandability (10 ports), but with a simple and clean design.

• Full USB 2.0/1.1 performance and compatibility. No compromises. Works on all platforms with no drivers (i.e. it’s a standard USB 2.0 hub)
• Cascaded Terminus Technology chipsets – the best designed, lowest power, most reliable USB 2.0 hub controller out there right now
• The 10 ports (plus upstream port to PC and AC power) are all on just two sides of the hub, minimizing cable clutter
• Two of the ports swivel to a vertical position – so if you want a flash drive or antenna to stick up, that works. If you want everything to lay flat so you can stack on the hub, no problem
• A blue LED bar down the center of the device signals power. 2.5A AC adapter included

The customer feedback from this hub design has been surprising us – you wouldn’t think in 2010 that a USB 2.0 hub could get people excited. But buyers have written with disproportionately positive feedback like “Easy to use and a really helpful device” and “Exactly what I was looking for”.

With many laptops only having 2 or 3 USB ports, the easy expandability of a hub like this is a nice win.

Check out more pics and details on the Amazon product page

Plugable USB 2.0 10 Port Hub (with Power Adapter)

Product Details

$26.95

Support for these devices has been in the Linux kernel since kernel 2.6.21 (file /drivers/net/usb/asix.c). However, prior to version 3.2, this driver fails to find an IP address, and comes up “disconnected”

To get the adapter working, we need to download, compile, and install the latest driver available from ASIX for the AX88X family. This driver is compatible with kernels 2.6.14+

Steps

Assumes you have another net connection on this machine. Download the driver on another machine and copy over if not.

mkdir asix
cd asix
wget http://www.asix.com.tw/FrootAttach/driver/AX88772B_772A_760_772_178_LINUX2.6.35_Driver_v3.5.0_Source.tar.bz2
tar xvjf *
sudo apt-get install module-assistant
sudo module-assistant prepare
sudo modprobe -r asix
make
sudo make install
sudo modprobe asix

Your USB network interface should now come up automatically.

These instructions have been written for our Plugable USB2-E1000 USB Gigabit Ethernet adapter, but should apply to any ASIX adapter with an ASIX AX88178 USB Ethernet controller and Realtek RTL8211CL PHY, which reports ASIX’s USB IDs VID_0B95 & PID_1780.

The steps should work identically on older Ubuntu kernel versions. It was also tested on Ubuntu 9.04, kernel 2.6.28.10. Comment here if you have any trouble, and we’ll try to figure it out.

Common errors

Before this update of the driver, the common errors you’ll see typically show up as a timeout trying to get an IP address from DHCP. You’ll see messages like

“no ipv6 routers present” in dmesg and /var/log/kern.log

And in /var/log/syslog:
“DHCP transaction took too long (>45s), stopping it”
“Marking connection ‘Auto eth1′ invalid”

Again, this update of the ‘asix’ kernel module should resolve these errors. For the future, hopefully the in-kernel ASIX driver will get patches to catch it up with the driver source available directly from ASIX.

We know how much work open source driver development is — getting hardware should be the easiest part of it. So today we’re announcing a new program to better get test devices out to developers who can use them.

If you’re a developer with a history submitting patches for Linux or other platforms, please submit your request for Plugable sample hardware here. Because we’ll have only a trickle of each type over device over time, an important part of this is having some idea of what prior driver development contributions you’ve made. We’ll try to focus on matching hardware to the developers most likely to be able to contribute improvements in that area.

Plugable’s products cover a fairly wide range of USB and other devices. See http://plugable.com/shop/ for our products that will be available from time to time under this program.

We’ve long been doing this kind of thing with the commercial vendors. Having worked on Windows and at Microsoft, we try to drop off samples to get them using, testing, and developing against our hardware. We’d do the same for Apple or others. This is our attempt to get these same benefits going with the wider open source community.

We hope this will seed some good things over time. And we welcome any feedback or suggestions on this program anytime.

Linux is a big and constantly shifting platform. With our USB graphics products (and generally for DisplayLink based products, since we try to make them work for all devices), it’s easy to output a few pixels, but configuring a USB display as an X terminal, or certainly for an extended desktop, is still a process on Linux that requires manual xorg.conf editing and is for very advanced users only. But we try to contribute what we can at Plugable, and that has meant focusing on making the kernel driver that actually talks to the hardware and everything else builds on, as solid as possible.

The contributed patches start with this post to the linux driver project list.

————–
To: devel-request@linuxdriverproject.org
[PATCH 0/11] staging: udlfb: patches from udlfb development branch (Bernie Thompson)

This patch series contains all current fixes and features from
the udlfb development branch.

udlfb is a framebuffer driver for DisplayLink USB 2.0 era chips.

Diffstat of this 11 part patch series:

udlfb.c | 989 +++++++++++++++++++++++++++++++++++++++++———————–
udlfb.h | 41 +-
2 files changed, 664 insertions(+), 366 deletions(-)

Major changes:

* Added summary documentation for users of udlfb
* Added logic to query DisplayLink chip for max area mode,
so low-end chips on high-end monitors no longer get black screen
* Added support for DPMS. X servers now control monitor
power with existing standard interface
* Added back in support for char interface (e.g. cat file > /dev/fb0)
* Systems without EDID or with failing EDID can now supply fixed
EDID to sysfs interface, also avoiding black screen
* Fixed big-endian (PowerPC) rendering
* Fixed teardown race conditions that could result in shutdown hang
* Added fb_defio and fb console module options (default off)
* Fixed udlfb’s fb_defio client code so no longer incorrectly shares
state across udlfb device instances – fixes hangs and errant rendering
* Removed IFDEFs for building against older kernels – those will
be retained in the udlfb development branches at git.plugable.com

Todo:

There have been no additional reported bugs in the last few months,
although there are several wishlist features. Udlfb may be ready
to move out of staging at this point.

Patches are against Linus’ latest 2.6 tree.

This complete quilt patch series can be downloaded from http://plugable.com/udlfb-patches-2.6.35-v2.tgz

Plugable UD-160-A driving 1920x1080 display and more, all from a humble Nexus One phone

This setup uses the udlfb DisplayLink Linux driver work from here (git.plugable.com) and a bunch of other components Sven has developed or pulled together, to turn the phone into a full computer with display, keyboard, audio and more. His video of this has gone viral (over 85,000 views). You can see the video and full instructions at Sven’s site. Very cool.

The photo above is of the Plugable UD-160-A Universal Docking Station, in use at Sven’s desk (the dock is laying on its side to better fit in the photo – Sven has removed the weighted bottom stand).

The Plugable dock is perfect for this kind of application with the Nexus One phone — it includes all the USB devices in one place, all with open source drivers. The dock has its own 2.5A AC power (see the USB dual-power Y cable plugged into the front USB A and back USB B ports), along with driving the 1920×1080 monitor (the big DVI cable in the back), and providing ethernet (above the DVI) and audio (in the front – he doesn’t have them plugged in in the pic).

So this all is great for geeks, but when will this work out of the box? Several comments on Sven’s work are messages like “Google! Integrate this into Android now!”

With Google offices near here, and with related USB terminal work on the same Plugable dock being funded as a Google Summer of Code project, it would be great to demo this and get things moving… Whatcha say, Google!?

Last year, he demoed turning your router into a full-fledged computer.

This year, it’s the Google Nexus One phone as a full computer — with attached external keyboard, mouse, display, and more.

The Nexus One demo is using the udlfb Linux kernel module to talk with the DisplayLink device, and it will work with any DisplayLink device, including Plugable’s.

Note the version of udlfb in the 2.6.34 staging tree unfortunately didn’t work for Sven. So he’s now using the latest udlfb from http://git.plugable.com/, which will likely get merged in for kernel 2.6.36.

Also, he used a dual headed cable to get enough power. A powered hub or a docking station/terminal like the UD-160-A won’t need that — it supplies its own power from AC – all the hardware needed is in the one package.

It’s exciting to have all this open source work come together in interesting demos like this.

There was a question recently why udlfb doesn’t use the same compression technique as the Windows drivers. Among other reasons, one is that the RL compression used by udlfb scales down to devices like the ones Sven has been working on — it’s as light as possible on CPU load, while getting decent compression.

Stepping back, it’s clear Apple (and now Microsoft) are making a mistake by limiting the hardware ecosystem around their devices. Android and the other Linux variants have an opportunity here — and considering the Apple juggernaut, they definitely need every advantage.

Sven’s demos show how powerful these scenarios can be. The hardware is ready. Devices like Plugable’s are designed with these scenarios in mind. Now we need to get the software refined and included in standard distributions, so normal consumers can take advantage of all the possibilities and benefits here.

The goal of their project was to get an embedded platform working on Centos 5.3. You can read more in their release note for the work.

To make the contributions easier to diff, they’ve been checked into a git branch from a (best guess) of the code Endurance started from.

The changes are available here for the kernel driver and here for the X server.

To actually build it, you may need their full package.

It’s unclear what of these changes might get picked up, as things have moved on since. One of the main features of this code is providing a default EDID blob in udlfb. The plan for udlfb at this point is to allow the edid sysfs interface of udlfb to be written to, to allow (and give responsibility) to a user-mode entity to supply a default edid, if one isn’t available from hardware.

Thanks again to Endurance for being diligent about contributing changes back.

We’re very excited about the Google funded project to refine USB multiseat on Linux, with the winning proposal from Lucas Nascimento Ferreira at the Federal University of Parana in Brazil.

In addition to providing mentoring, Plugable is also providing donated hardware for this project. Two Plugable Universal Docking stations with recent enhancements for use as a terminal, were just picked up by Lucas in Brazil today. By next month, we expect to have updated versions of the UGA-125-HUB for terminal use to send down.

For those interested in learning more and potentially following Lucas’ work:

• Google’s SoC 2010 Timeline
• Lucas’ winning USB Multiseat Proposal

And we’ll post periodic status updates here.

We do this because we know you use a mix of machines, or may be thinking about switching one way or another. And when you invest in a collection of USB devices, you want them to be useful beyond your current computer. That’s what we expect, too.

All this activity can get a little noisy, though. A little too much information.

That’ll be especially true for some exciting but technically involved work that’s happening over the next few months on Linux with the Google Summer of Code project for USB multiseat, which makes use of some of our Plugable hardware.

So if you’re interested in just one platform or another, here is a way to get just the news that you care about, and get rid of the rest of the noise:

•  Subscribe – Windows News From Plugable
•  Subscribe – Mac News From Plugable
•  Subscribe – Linux News From Plugable

And for those wanting an even more customized view — just append /feed to the tail end of any category view on the site, to get an even more specific feed, if you’re interested.