ThinkPad x200 w/ docking station on Arch: missing drivers?

shako · 2022-05-16 13:42:42

Hi everyone,

I ma trying to connect two external monitors to my ThinkPad x200 running Arch through a docking station (Lenovo Ultrabase).
I connected the first monitor through the VGA port of the ultrabase, and it worked just fine. Then, I tried connecting a second monitor through the VGA port on the actual laptop, and this time it didn't work. I suspected it was not possible to connect two VGA cables at the same time, and I tried connecting the second monitor through the display port of the docking station: still nothing. Not only there is no output on the screen, but the monitor isn't even recognized by xrandr. Even after disconnecting the working VGA port, I can see no output from the display port.
Moreover, the VGA port of the laptop works only if it's not attached to the ultrabase: in that case, the only avaiable VGA port seems to be the one on the ultrabase. I also noticed that none of the USB ports on the ultrabase are working (I tested them all w/ an external keyboard): only the ones on the laptop are avaiable while it is connected to the ultrabase. It seems that some ultrabase ports (i.e. VGA or ethernet, which I am currently using) are supported by default, while others aren't.

I got the ultrabase second hand, but revised and good as new, so I think there is little chance that it's broken. May I be missing some kernel modules for "docking station support" to support the additional ports provided by the ultrabase (assuming they exist)? Or is it an "issue" of the actual motherbord, which won't allow me to "split" the input/output over a certain number of ports?

Thanks to anyone who will reply

Last edited by shako (2022-05-16 13:48:38)

nordkamp · 2022-05-17 10:26:20

Hi there. Seems for DisplayPort in this particular docking station you need to pass modeset=1 to the i915 intel gpu driver, if you aren't already.
If you don't know how, the file to edit is /etc/default/grub and inside GRUB_CMDLINE_LINUX_DEFAULT you want to add "i915.modeset=1" without quotes. Then run the command:

sudo grub-mkconfig -o /boot/grub/grub.cfg

and you should be good to go.

Hopefully this fixes your issues!

Slithery · 2022-05-17 10:48:12

What makes you think that the OP is using grub? They could be using another bootloader.
A better reply would be to just link to the wiki page which explains the steps needed for all bootloaders...
https://wiki.archlinux.org/title/Kernel_parameters

nordkamp · 2022-05-17 11:03:17

Slithery wrote:

What makes you think that the OP is using grub? They could be using another bootloader.
A better reply would be to just link to the wiki page which explains the steps needed for all bootloaders...
https://wiki.archlinux.org/title/Kernel_parameters

Point taken, but OP is using a Thinkpad X200. Neither rEFInd nor systemd-boot support non-UEFI based systems, and the others that do are pretty obscure in comparison to GRUB so it was just an assumption on my part.
If he's using something like syslinux he probably knows how to set kernel module options

Last edited by nordkamp (2022-05-17 11:07:05)

shako · 2022-05-17 12:00:54

nordkamp wrote:

Hi there. Seems for DisplayPort in this particular docking station you need to pass modeset=1 to the i915 intel gpu driver, if you aren't already.

Hi @nordkamp, thank you for your answer. You got it right! I am using GRUB. I tried following your suggestion and added this line to my /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux i915.modeset=1"

Then I ran grub-mkconfig and rebooted, but the DP monitor remains off. I suspect there is something wrong w/ my syntax? Or my motherboard can't support additional video outputs?

nordkamp · 2022-05-17 12:09:10

shako wrote:

Then I ran grub-mkconfig and rebooted, but the DP monitor remains off. I suspect there is something wrong w/ my syntax? Or my motherboard can't support additional video outputs?

Checking if the parameter was set properly is quite easy, have a look at the output of this command:

sudo systool -v -m i915 | grep modeset

If this shows that modeset is set to 1, we likely need to find a different solution...

shako · 2022-05-17 12:15:41

Yup, it shows 1. Here's the full output:

force_reset_modeset_test= "N"
modeset             = "1"

I tried rebooting and disconnecting the VGA port, connecting a single monitor through the display port, and that didn't work: so I think it's not that the two (VGA and DP) can't work together, it's the DP which is still "locked" for some reason

Last edited by shako (2022-05-17 12:16:10)

nordkamp · 2022-05-17 12:30:03

shako wrote:

Yup, it shows 1.

Any change in xrandr after enabling this?

shako · 2022-05-17 12:32:39

No, every DP entry is marked as "disconnected" as for the previous cases (sorry, I forgot to mention it in my previous message).

EDIT: not sure if that's helpful, but if I disconnect the VGA cable (regardless whether the DP cable is connected or not), I get the following 2 lines appended to the output of xrandr:

1024x768 (0x552) 78.750Mhz +HSync +VSync
h: width 1024 start 1040 end 1136 total 1312 skew 0 clock 60.02KHz
v: height 768 start 769 end 772 total 800 clock 75.03Hz

Last edited by shako (2022-05-17 12:38:24)

Arch Linux

#1 2022-05-16 13:42:42

ThinkPad x200 w/ docking station on Arch: missing drivers?

#2 2022-05-17 10:26:20

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#3 2022-05-17 10:48:12

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#4 2022-05-17 11:03:17

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#5 2022-05-17 12:00:54

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#6 2022-05-17 12:09:10

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#7 2022-05-17 12:15:41

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#8 2022-05-17 12:30:03

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

#9 2022-05-17 12:32:39

Re: ThinkPad x200 w/ docking station on Arch: missing drivers?

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