How to disable DisplayLink driver for Ubuntu 10.10?


#1

Hello,
I have a 2010 Macbook Pro, running Mac OS X, Windows 7 and Ubuntu 10.10 with the Plugable UGA-2K-A. This works excellently with Mac OS, and Windows 7. I have had it working with Ubuntu, but it very finicky. If I change my setup (meaning, boot as laptop only, no 2nd screen) Ubuntu gets all confused.

My question. How do I disable DisplayLink in Ubuntu 10.10? After the next iteration of the driver, I may try again.

Thank you,

Craig


#2

Hi Craig,

Thanks for posting! It would be helpful to see more about how you have Ubuntu 10.10 configured - how it is getting confused? (normally, we’d expect 10.10 to just show a “green screen” and perhaps take over the console, more than that requires hand configuring)

Because Linux X configuration for USB devices is static, not dynamic, simply disabling a device might not get the result you want, but the way you can disable Linux’s in-kernel driver is with these two commands:

echo “blacklist udlfb” > /etc/modprobe.d/udlfb.conf

update-initramfs -u

Now you’ll no longer see a green screen, as no driver will match against the dispaylink devices.

Then, if X still has a problem, you’ll want to backup then delete the custom xorg.conf you must have created. That will cause X to fall back to automatic PCI graphics configuration (with no knowledge of USB displays).

Hope that helps. Thanks!
Bernie


#3

Hi Bernie,

Thanks for your prompt reply! Here is the back story…

I am using a Henge Dock for my Macbook. I did do some hand configuration and had everything working with 2 monitors (one using mini-DVI, the other USB Plugable). I usually boot into Mac OS X, and it works great! I sometimes get a fuzzy monitor (either one), but after a several seconds that clears up. Also, for the record Windows 7 works every time. (Though I am not a real fan of Windows, much more an OS X, linux guy.)

The problems started when I ran the Macbook as an Ubuntu laptop, lid open, with the mini-DVI attached to my HD TV (for Boxee). I wasn’t thinking, and I used the NVidia configurator, without properly backing up my existing configuration!!!

The configurator added some typo errors to the xorg.conf, (I selected merge, rather than write a new one). I did a rescue boot, so I could see the errors on startx, I removed the errors, and got it partially working.

By the way, I do see the DisplayLink taking over the console (after boot). I do not see the GRUB prompt, before that. Just this afternoon, I did get it to boot into a Green screen (is that a good sign?).

Anyway, now I figure the best solution for Ubuntu, is to not use the USB monitor for now. And wait for another DisplayLink driver update. I do not use Ubuntu on this laptop that often, and I do expect to use Ubuntu in true laptop mode.

I will try your suggestions and see if I can get it working with the mini-DVI monitor in the Henge Dock.

Thank you for an excellent product! I am very happy with it’s performance with the 2 main stream operating systems. Hopefully a later DisplayLink driver will improve the Linux, but it may also be due to an interaction with the NVidia driver.

Thanks again,

Craig

Ps. I will post again, once I get things sorted out.
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Update: 9:580pm
Ok, I made your suggested change in modprobe.d, then re-configured using the NVidia configuration tool. I added another Gnome Panel, to the 2nd screen and dup’d the needed items.

PPs. 2/15/11 8:16am
Ooops, forgot to run the 2nd command you suggested! Going to try again. I guess I was tired last night

Thanks for your help!

Craig


#4