Unfortunately, on Mac OS X, there is a conflict between recent DisplayLink drivers 1.5+ and the Apple drivers (AppleUSBEthernet) for ASIX chips. The DisplayLink drivers appear to open other USB devices as part of enumeration. As a side effect, this causes USB ethernet devices to show as “disconnected” upon return from system boot or hibernate.

That’s in addition to other graphics and ethernet driver compatibility breaks that Apple’s recent OS X 10.6 updates have introduced, including breaking AppleUSBEthernet for non-Apple USB ethernet hardware.

Until these issues settle down and are fixed in the drivers from DisplayLink, ASIX, and Apple, here is a workaround for the current issues with the ethernet function of the Plugable Universal Docking Station:

Step 1 is to download and install ASIX drivers that are compatible with recent Mac OS X 10.6: http://plugable.com/wp-content/uploads/2010/04/AppleDefaultDriver_v2.1.5.zip

Step 2 is to copy the following script to a file (call it “install”), and run “sudo ./install”

#!/bin/bash
sudo echo "#!/bin/bash" > /usr/bin/plugable-eth-reset
sudo echo kextunload -b com.apple.driver.AppleUSBEthernet >> /usr/bin/plugable-eth-reset
sudo echo kextload -b com.apple.driver.AppleUSBEthernet >> /usr/bin/plugable-eth-reset
sudo chown root /usr/bin/plugable-eth-reset
sudo chmod o+x /usr/bin/plugable-eth-reset
sudo defaults write com.apple.loginwindow LoginHook /usr/bin/plugable-eth-reset

Now, logging out and logging back in will automatically reload the ethernet driver. Unfortunately, this does not cover the return from low-power cases. Unless we find an improvement to the workaround, you’ll have to log out/log in or just run “sudo /usr/bin/eth-reset” so trigger the script.

As there may be variations in systems out there, please comment if you get different results, and we’ll post an update here at Plugable if (as we hope) this is fixed more directly in the DisplayLink or ASIX drivers in the future.

And, generally if you’re a Mac OS X user, please be cautious about OS updates which might break 3rd party hardware drivers. If you have non-Apple USB hardware, consider deferring updates until there’s time for other people to report on forums about compatibility.

Linux hasn’t had that support — it would try to set the highest mode the monitor is capable of, often resulting in a black screen. Especially common for the DL-125 chip, with its mode limits of 1440×900/1280×1024.

That’s a shame because the DL-125 chip is a smart choice in many cases – by limiting itself to those lower modes, it stays more consistently within the limits of the USB 2.0 bus, resulting in more consistent performance.

So coinciding with the launch of Plugable’s DisplayLink DL-125 based products (UGA-125 and UGA-125-HUB), changes have been implemented to bring Linux roughly up to the level of Windows and Mac in this area for DisplayLink devices. This also helps devices like the UD-160-A when running on monitors greater than its limit of 1920×1080.

The kernel framebuffer driver udlfb has been enhanced to read the resolution limit from the firmware descriptors of the device, and adhere to it.

On the X server side, we needed a driver which would limit itself to the resulting reduced mode list. Unfortunately, the existing displaylink X server reads EDID directly, and assumes the adapter can do whatever the monitor can do.

We’ve been wanting to get rid of the need for a displaylink-specific X server, and the standard xf86-video-fbdev driver runs with the best existing mode, rather than trying to set a higher one in EDID. So this was a good trigger for converting over.

So xf86-video-fbdev has been enhanced with X Damage protocol support, ported from Roberto’s displaylink driver. This is still a little in-flux from an interface perspective, but from a functional perspective it’s done and fully performant.

So it’s now possible to run with a modified generic fbdev driver, which talks to udlfb, with full performance and without needing defio (although there’s also some good news in the defio space, which will be posted about later).

You can grab the latest udlfb kernel module with a “git clone http://git.plugable.com/webdav/udlfb”. Compile with “make && sudo make install && sudo depmod -a”

And you can grab the latest modified xf86-video-fbdev with a “git clone http://git.plugable.com/webdav/xf86-video-fbdev”. Compile with “./autogen.sh && make && sudo make install”

You’ll need a very recent xorg-macros version (1.4), which in package “sudo apt-get install xutils-dev”

To use the new X server, you must turn on the new “ReportDamage” option to fbdev. Modify your existing xorg conf like this:

Section "Device"
  Identifier "dl"
  Driver "fbdev"
  Option "ReportDamage" "true"
  Option "fbdev" "/dev/fb0"
EndSection

And you should be all set to go. This new X server should work with the existing udlfb in the staging tree of kernel 2.6.31+ for now, as it’s re-using the same original ioctl. But may require modeset changes that are only in 2.6.34+.

Some of our favorite tips from the article:

• Turn on Window’s “Show location of pointer when I press the CTRL key” feature
• The hotkey Win-[up, down, left, right] for maximizing, restoring and moving windows across monitors
• Their recommended links to find cool multimonitor wallpaper

In any case, it’s a must-read post for the multi-monitor aficionado.

This video shows two similar 2-monitor setups: the first using PCIe graphics, the other using Intel chipset graphics + a DisplayLink USB chip like the kind used in Plugable’s products.

The DisplayLink solution takes the power consumption from ~80W down to ~50W. Over time, and as you add more monitors, that’s a huge savings.

Read more about this at http://www.displaylink.com/power_saving.html

DisplayLink users on Mac might want to hold off on Apple’s update until any problems are shaken out.

A few things that have evolved since the video:

* Windows Vista, Windows 7, and Mac support
* Open Source exists for programming the DisplayLink chips
* It’s hard to find monitors with DisplayLink integrated, but it’s easy to find the adapters that work with any monitor (like our UGA-2K-A, which uses the DisplayLink DL-195 chip)
* The video showed an adapter with only VGA out. Our provides the more flexible DVI out, and includes simple, passive DVI->VGA and DVI->HDMI adapters which work transparently.
* The video doesn’t talk about resolutions, but the newest chips like the DisplayLink DL-195 can hit higher resolutions and/or have higher quality motion video playback at lower resolutions.

And it’s still the best and easiest way to outfit a cool bat cave.

We use NTFS-3G on Mac OS 10.4 here, in combination with the Plugable USB 2.0 SATA All-in-one Storage Dock and large TB+ SATA drives. Along with built-in NTFS support on Windows XP and up, and all recent Linux distros, this lets us easily swap a single USB cable between Windows, Mac, and Linux and have all three be able to read and write the drive(s).

Overall, this is a good solution for developers who have to span multiple platforms, for people who use boot camp to switch between Mac and Windows, or for increasingly common multi-platform offices that are using external storage docks for backup.

And it’s nice having a both an open source and a (better performing) commercially supported option.

It used to be that the venerable FAT32 filesystem was best way to format a drive to make sure you could easily read and write it from Windows, Mac, and Linux. But FAT32 has some limits that are especially problematic for today’s large drives 1 TB and up:

• Hard limit of 4GB on any individual file (think home movies of 30 mins or more)
• FAT32 needs large cluster size for large disks – which means wasted disk space in the case of many small files
• Partition size limits that can get as small as 32GB, and certainly hit at 2TB

There are various ways to read and write filesystems native to one OS on another. But there are also lots of pitfalls. All things considered, NTFS is the best compromise today.

For more background:

• Windows FAT32 filesystem limits
• Windows NTFS filesystem limits
• Mac HFS+ filesystem limits
• Linux Ext filesystem limits

While those free adapters aren’t quite as nice as ours here at Plugable, but they’d still be a fun win.

And at the post there, you can get an idea what interesting things other people are doing with their USB-attached displays.

.. driver is found and downloaded from Microsoft’s Windows Update system…

… and a DisplayLink EULA and a bunch of screen flashes later …

Windows 7 and a network connection takes care of it. No driver disk needed.