Using Dell’s D/Dock docking station with Linux

Tux
Dell is shipping docking stations for it’s Latitude Laptops. I’ve tested a D/Dock and it does work with Linux. The only real problems have their roots in Linux’ shortcomings.

My new laptop has docking station support, and since these docking stations can be bought second hand at very reasonable prices I got myself a D/Dock.

It worked out of the box: the laptop, plugged to the docking station, just works. External devices connected via USB or the external monitor also work as they would be plugged directly to the laptop. I didn’t test the media bay, the DVI connector or the additional PCI slot, so I’m not sure if they would work. However, since there were no other problems I would at least be confident in trying these.

Hotplugging is also not an issue: the laptop can be plugged on or off the docking station while it is running. Of course, mounted USB devices connected to the docking stations should be unmounted before plugging off! But besides that there are no real problems.

The only real disadvantages of the docking station itself I was so far able to recognize are that it has too few USB ports and that it is a bit noisier than I would have expected.
There are just 3 USB slots at the back plus one at the side (which is a bit extended to work with Dell stuff, but still works as a normal USB slot), but I would have preferred to have at least 6. Mouse, keyboard, external hard disk, webcam, USB stick and a MP3 player are not uncommon devices these days.
The other problem is the noise of the docking station fan: while it is not really disturbing and far away from the fan of my former laptop it is at least noisier than the laptop’s fan. But since the docking station was quite cheap I might open it to check if I can do anything about it.

So basically everything works very well – however, there is one problem due to the shortcoming of Linux – or X to be more specific – itself: the external monitor is not detected and activated automatically. And the other way around, if the external monitor is activated alone and the laptop is unplugged, the laptop screen stays blank and there is no way to bring it back.
So the actual shortcoming is that, while the basic hotplugging support is available, there is too little automation there: X should make clear that at least one connected output device is active all the time! Also, there should be easy ways to define specific situations: if monitor xyz is connected, switch to xyz only, if monitor abc is connected, switch to abc and laptop monitor. The first one would be the external monitor of the docking station, the second one could be a projector.

But again, this is a problem due to Linux, not due to the docking station. I guess this will have to wait until the proprietary drivers deliver XRandR 1.2 support and until the distributions ship XRandR 1.2 GUIs at a larger scale and really implement these into the system. Fedora 9 will ship with a Gnome interface, and afaik KDE 4 has basic XRandR 1.2 support anyway. Still, I’m not aware of any demon like capabilities to enable automatic device selection as mentioned above…

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13 thoughts on “Using Dell’s D/Dock docking station with Linux

  1. I have an similar setup: D630 with nvidia but with a cheaper D/Port [1] port replicator. I’ve found using TwinView and nvidia-settings to be a relatively easy way to switch between the laptop screen and external monitor. As you mention, hopefully the dock/undock situation will get better when XRandr 1.2 gets more support from drivers.

    However, my biggest problem is docking/undocking doesn’t reconnect by USB keyboard and mouse. If I boot when docked, everything works fine. When I re-dock from standby or hot, my USB devices aren’t found. I have no idea how to fix the situation unless I reboot, which is pretty annoying. Of course, everything works in Vista. :(

    Maybe I should get the D/Dock you linked to if that really doesn’t have the USB reconnect issues.

    [1] D/Port

    http://accessories.us.dell.com/sna/products/Docking_Station/productdetail.aspx?c=us&l=en&s=biz&cs=555&sku=310-7704

  2. Hi Kevin – I booted the laptop from within the docking station, hot-unplugged it, plugged it in again, and the USB mouse and keyboard were still running. I can also test specific cases if you want me.

  3. Oddly enough, the problem seems to have gone away just in the past two days and I’m not sure why. I’m back to just having the external monitor not be detected.

  4. No luck here. I’m on Ubuntu 8.04, and the d/dock is almost completely unsupported. Only USB seems to work, and even then it’s unreliable. The issue seems to be Linux has no idea how to handle the docking/undocking procedure. If I dock/undock with Linux running, everything becomes unresponsive and I have to do a forced reboot. I can’t tell if X has crashed or it’s just in some sort of suspend mode.

  5. Chris, does the dock work when you boot with the computer already docked?
    Is the docking support activated in the bios?

  6. I spoke too soon. My docking+USB problems seem related to suspend/resume, but I haven’t narrowed it down yet.

  7. I just wanted to say that I am experiencing the same thing. I have an Inspiron 600m with a D/Dock. When I had Ubuntu 7.10 installed I could hot dock without any problems, but with 8.04, if I try to hot dock my system freezes (usb kb, usb mouse, laptop kb, laptop touchpad are unresponsive) and I have to reboot.

    However, if I suspend my system, hot dock, and then resume, there isn’t a problem. My guess is that 8.04 isn’t checking/recognizing it’s I/O when it hot docks the way it does when waking from suspend.

    But what do I know?

  8. ac1971, in that case it could be an Ubuntu bug – report the problem at their launchpad, and they might solve it together with you.

  9. Hi,

    I have Kubuntu 8.04 (upg from 7.10) installed on a d610 laptop using the intel graphics. When I dock the laptop and boot it up, the external screen works at first. Then it blanks out and says “unsupported resolution.” If i switch back to the laptop it runs fine though. That said, I made changes in “system settings” for the display properties and specified the brand of the external monitor, and set the resolution. It still won’t show on the screen. What wa is there to work around this, or get it to display on my screen properly?

    Thanks

  10. Sandro, can’t help you there since I’m not having hte Intel drivers and not using Kubuntu. The best would be to test the external monitor without the docking station. If the problem persists, ask at the ubuntu forums, they are very good.

    If the problem does not persist, then your docking station might be broken.

  11. I am using D820 and docking station.
    20″ DELL connect via dvi to the docking station.
    The problem is when i install ubuntu, it can’t recongise the 20″ DELL (i have the laptop screen folded down).
    i can see the boot screen but when it go to login screen nothing happen on the screen.
    help please.

  12. If you have (after unplugging a dock or switching off a video-projector) a blank X screen, you can try the following tip:
    - switch to a console (C-A-F1)
    - login as the same user as the one in X
    - export your display. In bash, with one default screen:
    export DISPLAY=:0
    - change your settings with xrandr:
    xrandr
    xrandr –output VGA –off –output PANEL –auto …
    - logout the console
    - go back to the X screen (C-A-F7)

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