Maximum number of displays?

[Chen]

Hello Friends!

I have a bit of a problem when it comes to getting 3 display link DL6 dual hdmi port devices to work properly in RHEL and in Ubuntu. Both exhibit the same issue.

The issue that I'm facing is that out of the 6 properly connected monitors via displaylink 4 only work and show up on the list of available monitors.

If I where to unplug 1 displaylink USB device the non working monitor would work.

It feels like there's a cap of only 4 monitors... I've attempted adjusting the initial monitors in evdi.conf and to no avail.

To make matters more interesting, if you'd take the same machine with the same displays/configuration and load up windows everything works fine...

So why isn't Linux getting much love displaylink??

If it helps here is diagnostic stuff.

$ ls -1 /sys/class/drm
xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
card0
card0-DP-1
card0-DP-2
card0-DP-3
card0-HDMI-A-1
card0-HDMI-A-2
card1
card1-DP-4
card1-DP-5
card1-DP-6
card1-HDMI-A-3
card2
card2-DVI-I-1
card3
card3-DVI-I-2
card4
card4-DVI-I-3
card5
card5-DVI-I-4
card6
card6-DVI-I-5
card7
card7-DVI-I-6
renderD128
renderD129
version
Screen 0: minimum 8 x 8, current 11520 x 1080, maximum 32767 x 32767
HDMI-1 connected 1920x1080+9600+0 (normal left inverted right x axis y axis) 1872mm x 1053mm
DVI-I-5-4 connected 1920x1080+7680+0 (normal left inverted right x axis y axis) 477mm x 268mm
DVI-I-4-3 connected 1920x1080+5760+0 (normal left inverted right x axis y axis) 477mm x 268mm
DVI-I-3-2 connected 1920x1080+3840+0 (normal left inverted right x axis y axis) 477mm x 268mm
DVI-I-2-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 477mm x 268mm
DP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 1872mm x 1053mm
1920x1080 60.00*+ 59.94 50.00 29.97 25.00 23.98
1920x1080 60.00*+ 59.94 50.00 29.97 25.00 23.98
1920x1080 60.00*+
1920x1080 60.00*+
1920x1080 60.00*+
1920x1080 60.00*+

[rboerner]

Originally Posted by Chen

Hello Friends!

I have a bit of a problem when it comes to getting 3 display link DL6 dual hdmi port devices to work properly in RHEL and in Ubuntu. Both exhibit the same issue.

The issue that I'm facing is that out of the 6 properly connected monitors via displaylink 4 only work and show up on the list of available monitors.

If I where to unplug 1 displaylink USB device the non working monitor would work.

It feels like there's a cap of only 4 monitors... I've attempted adjusting the initial monitors in evdi.conf and to no avail.

To make matters more interesting, if you'd take the same machine with the same displays/configuration and load up windows everything works fine...

So why isn't Linux getting much love displaylink??

If it helps here is diagnostic stuff.

Four displays is the maximum that DisplayLink supports under Linux. Please see this article for more information --> https://support.displaylink.com/know...ubuntu-support

"DisplayLink supports up to four monitors. It may be possible to connect and use more but this is not tested or supported by DisplayLink."