DisplayLink not working 2 external monitors

Kindlewing · 2022-12-12 17:21:04

I recently bought a Kensington Dock, and I'm trying to hook up the monitors to the dock.

  xrandr --listproviders

output is

Providers: number : 1
Provider 0: id: 0x56 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 4 outputs: 4 associated providers: 0 name:AMD Radeon Graphics @ pci:0000:06:00.0

xrandr --current output

is:

Screen 0: minimum 320 x 200, current 3840 x 2160, maximum 16384 x 16384
eDP connected primary 1920x1080+1920+1080 (normal left inverted right x axis y axis) 344mm x 193mm
   1920x1080     60.01*+
   1680x1050     60.01
   1280x1024     60.01
   1440x900      60.01
   1280x800      60.01
   1280x720      60.01
   1024x768      60.01
   800x600       60.01
   640x480       60.01
HDMI-A-0 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 530mm x 290mm
   1920x1080     75.00*   72.05    60.01    50.02    48.02    60.00    50.00    59.94
   1680x1050     59.88
   1600x900      60.00
   1280x1024     75.02    60.02
   1440x900      59.90
   1366x768      59.96
   1280x720      60.00    50.00    59.94
   1024x768      60.00
   800x600       71.99    75.00    60.32    56.25
   720x480       60.00    59.94
   640x480       60.00    59.94
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 530mm x 290mm
   1920x1080     75.00*   60.00    50.00    59.94
   1680x1050     59.88
   1600x900      60.00
   1280x1024     75.02    60.02
   1440x900      59.90
   1366x768      59.96
   1280x720      60.00    50.00    59.94
   1024x768      60.00
   800x600       71.99    75.00    60.32    56.25
   720x480       60.00    59.94
   640x480       60.00    59.94

HDMI-A-0 is connected to the HDMI port of my laptop, DisplayPort-1 is connected to the dock, and DisplayPort-0 is the one that's not connected (although it's plugged into the dock, and it's the one that should be working)

Last edited by Kindlewing (2022-12-13 14:42:18)

Lone_Wolf · 2022-12-13 11:34:41

I recently bought a Kensington Dock, and I'm trying to hook up the displaylink monitors. I've followed the DisplayLink page on the wiki, and

DisplayLink monitors don't exist, you're confusing DisplayPort and DisplayLink .
DisplayPort is a standard protocol/connector for monitors, while DisplayLink is a manufacturer of usb-based devices that allow to connect extra monitors.

In theory Kensington could use displaylink devices in their docks, but that would mean Kensington has to pay DisplayLink and probably put the displaylink logo on the dock .
(I'd be very surprised if kensington does that.)

Unless the documentation that came with the dock does mention displaylink explicitly, remove anything displaylink related .

What is the model and type of your Kensington dock ?
Do you have latest firmware for it installed ?

Welcome to archlinux forums

Last edited by Lone_Wolf (2022-12-13 11:36:42)

Kindlewing · 2022-12-13 13:00:53

The dock is a Kensington SD5700T. Given that it's new, I think the latest firmware is installed, although I don't know how to update it on arch if it's not. The ports on the back that the monitors connect to are USB-C thunderbolt4 DFP ports, and I'm using usb-c to HDMI to connect the monitors.

seth · 2022-12-13 14:19:39

As Lone_Wolf pointed out, remove all the DisplayLink stuff - that has nothing to do with your situation.
The try to remove the HDMI output and see whether the second output from the dock shows up.
Also flip the output connections to the dock (to see whether one output or one jack is affected)

What kind of monitors are these? Same model?

Last edited by seth (2022-12-13 14:19:51)

Kindlewing · 2022-12-13 14:45:06

They are Sceptre monitors, capable of a 75 Hz refresh rate. The dock uses usb-c connectors on the back for monitors, so I'm using usb-c to HDMI cables. The dock manual says that it supports 2 4k displays at 60 Hz or 1 8k display at 60 Hz. I'm pretty sure these monitors are not 8k, so that shouldn't be the issue.

seth · 2022-12-13 15:04:00

I was more concerned that one of the outputs would not activate in response to the signal (or be too slow)

seth wrote:

Then try to remove the HDMI output and see whether the second output from the dock shows up.
Also flip the output connections to the dock (to see whether one output or one jack is affected)

Also

I'm using usb-c to HDMI cables.

try to flip those ('cause of rule #1 …)

Kindlewing · 2022-12-13 16:03:33

What do you mean by flip ? the only inputs the monitors have is HDMI, so HDMI to usb-c is the only option here.

seth · 2022-12-13 16:08:36

Use the other cable for each output. (Rule #1 says that the cable is likely broken)

Kindlewing · 2022-12-13 16:58:29

I tried switching the cables to no avail. I should mention that only one monitor works at a time, not two. If I unplug one cable, the other monitor kicks in, and vice-versa. It leads me to believe that either the monitors are indeed 8k (although I think that's unlikely) or the monitors default to 75 Hz, thus only one would be active at a time.

seth · 2022-12-13 17:04:26

seth wrote:

seth wrote:
Then try to remove the HDMI output and see whether the second output from the dock shows up.

Kindlewing · 2022-12-13 18:28:06

Still the same issue. My arandr script that I'm trying to use is

   
#!/bin/sh
xrandr --output eDP --primary --pos 1920x1080 --output DisplayPort-1 --pos 1920x0 --rotate normal --output DisplayPort-0 --pos 0x0 --rotate normal

Again, DisplayPort-0 is active, and DisplayPort-1 is disconnected, despite being connected via the cable. I've verified that both cables work, and the HDMI input is removed.

The output of

xrandr --current

is

 
Screen 0: minimum 320 x 200, current 3840 x 2160, maximum 16384 x 16384
eDP connected primary 1920x1080+1920+1080 (normal left inverted right x axis y axis) 344mm x 193mm
   1920x1080     60.01*+
   1680x1050     60.01
   1280x1024     60.01
   1440x900      60.01
   1280x800      60.01
   1280x720      60.01
   1024x768      60.01
   800x600       60.01
   640x480       60.01
HDMI-A-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 530mm x 290mm
   1920x1080     75.00*   60.00    50.00    59.94
   1680x1050     59.88
   1600x900      60.00
   1280x1024     75.02    60.02
   1440x900      59.90
   1366x768      59.96
   1280x720      60.00    50.00    59.94
   1024x768      60.00
   800x600       71.99    75.00    60.32    56.25
   720x480       60.00    59.94
   640x480       60.00    59.94
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
   1920x1080_60.00  59.96

seth · 2022-12-13 20:21:40

So it's not the crt nor the outputs nor the cables connecting the output.
=> Either the connection between the system and the dock or the dock itself.

This here seems relevant:
https://www.reddit.com/r/UsbCHardware/c … ce_book_3/
What is the actual connection between the notebook and the dock?

I think the latest firmware is installed, although I don't know how to update it on arch if it's not

Do you know how to check the firmware version?

Kindlewing · 2022-12-13 20:53:09

Thanks for this. I'll have to look at that post and dig a little deeper into my setup. At the bottom of that post, someone said that they spoke with Kensington, and they said that there's no firmware updates available. I'm not sure if that's changed since. Either way, I'm not sure how to check the firmware version.

seth · 2022-12-13 20:57:19

The crucial bit in the thread is, afaiu, that you can only use 2 outputs if the dock is connected via thunderbolt, not usb.

Arch Linux

#1 2022-12-12 17:21:04

DisplayLink not working 2 external monitors

#2 2022-12-13 11:34:41

Re: DisplayLink not working 2 external monitors

#3 2022-12-13 13:00:53

Re: DisplayLink not working 2 external monitors

#4 2022-12-13 14:19:39

Re: DisplayLink not working 2 external monitors

#5 2022-12-13 14:45:06

Re: DisplayLink not working 2 external monitors

#6 2022-12-13 15:04:00

Re: DisplayLink not working 2 external monitors

#7 2022-12-13 16:03:33

Re: DisplayLink not working 2 external monitors

#8 2022-12-13 16:08:36

Re: DisplayLink not working 2 external monitors

#9 2022-12-13 16:58:29

Re: DisplayLink not working 2 external monitors

#10 2022-12-13 17:04:26

Re: DisplayLink not working 2 external monitors

#11 2022-12-13 18:28:06

Re: DisplayLink not working 2 external monitors

#12 2022-12-13 20:21:40

Re: DisplayLink not working 2 external monitors

#13 2022-12-13 20:53:09

Re: DisplayLink not working 2 external monitors

#14 2022-12-13 20:57:19

Re: DisplayLink not working 2 external monitors

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