DisplayLink Forum - 1.4 not working (Ubuntu/Dell D6000)

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- - 1.4 not working (Ubuntu/Dell D6000) (https://displaylink.org/forum/showthread.php?t=65616)

1.4 not working (Ubuntu/Dell D6000)

I have used previous version of the driver with moderate success (random disconnects, high CPU usage, other than that it was working after I applied a patch fixing the compilation of evdi kernel module).

Unfortunately, I can't make 1.4 working on the very same system. Displays are always black, and xrandr --listproviders / --listmonitors does not show anything about external displays. I have checked everything I can, tried it with various kernel versions, waited for some time, tried disconnecting and reconnecting the dock etc. -- no luck so far.

I am seeing other users with similar configurations (Dell D6000 dock and a Dell laptop on a recent Ubuntu) succeeded in making it work.

Please help.

After removing the old and new driver, and reinstalling it from scratch, I now have one monitor working, but not another (I have two identical monitors connected to D6000 dock in the same way). I have checked that it's not the monitor to blame (if I swap the two connectors at the D6000 side, the other monitor lits up).

I noticed that the following happens for one monitor but not the other:

[ 3590.453526] evdi: [D] evdi_painter_mode_changed_notify:505 (dev=2) Notifying mode changed: 1600x1200@60; bpp 32;
[ 3590.453528] evdi: [D] evdi_painter_mode_changed_notify:506 pixel format 875713112
[ 3590.453542] evdi: [D] evdi_painter_crtc_state_notify:481 (dev=2) Notifying crtc state: 0
[ 3590.453545] evdi: [D] evdi_painter_dpms_notify:468 (dev=2) Notifying dpms mode: 0
[ 3590.553575] evdi: [D] evdi_detect:75 (dev=2) Painter is connected
[ 3590.553578] evdi: [D] evdi_painter_get_edid_copy:215 (dev=2) 00 ff ff

Again, I tried everything including numerous reboots of every piece of equipment (monitors, laptop, dock), reconnecting the cables, etc. Is there anything I can debug?

Second monitor still not working. Here are logs.

In general, DLM 1.4 is an improvement, especially in CPU load -- it no longer hogs CPU for nothing, only when there's activity on the monitor. If I can only have my other monitor working...

Quote:

Originally Posted by k001 (Post 84409)

Same here.

TP Carbon with TP Ultra Dock. Only one Monitor is working.

Back to 1.3.54 -> everything works nice except CPU usage.

JEns

Is there anything that I can try? I do miss the real estate of my second monitor, and the D6000 dock works like an el cheapo USB hub for now :(

This is intriguing. A few questions...

Are two screens operational with the older 1.3 driver but identical version of all other packages?
Does the second screen start to work if you restart X when one screen is up and running?
What's the contents of /sys/devices/evdi/count?
What's the output of ls -la /dev/dri?
With one screen running, what happens if you run (as root):

Code:

echo 1 > /sys/devices/evdi/add

possibly after replugging the USB cable after running it, too?

Thanks,
Michal

Hi Michał,

Thanks for looking into it.

Quote:

Are two screens operational with the older 1.3 driver but identical version of all other packages?

I will try it later today and report back. One problem is I'm using 4.10+ kernels so I'll need to patch the older evdi to be compilable with newer kernels (not a big deal).

Quote:

Does the second screen start to work if you restart X when one screen is up and running?

I never made it working with a new driver.

Quote:

What's the contents of /sys/devices/evdi/count?

Code:

kir@kd:~$ cat /sys/devices/evdi/count 

2

Quote:

What's the output of ls -la /dev/dri?

Code:

kir@kd:~$ ls -la /dev/dri

total 0

drwxr-xr-x   3 root root       140 Oct 17 23:43 .

drwxr-xr-x  20 root root      4280 Oct 18 10:29 ..

drwxr-xr-x   2 root root       120 Oct 17 23:43 by-path

crw-rw----+  1 root video 226,   0 Oct 17 23:43 card0

crw-rw----+  1 root video 226,   1 Oct 18 10:29 card1

crw-rw----+  1 root video 226,   2 Oct 18 10:29 card2

crw-rw----+  1 root video 226, 128 Oct 17 23:43 renderD128

Quote:

With one screen running, what happens if you run (as root):

Code:

echo 1 > /sys/devices/evdi/add

possibly after replugging the USB cable after running it, too?

No changes, except that card3 appears in /dev/dri, and some messages in dmesg:

Code:

[ 2943.659412] evdi: [D] add_store:239 Increasing device count to 3

[ 2943.659897] evdi: [D] evdi_crtc_init:351 drm_crtc_init: 0

[ 2943.660676] evdi: [W] evdi_painter_crtc_state_notify:484 Painter does not exist!

[ 2943.660686] evdi: [D] evdi_detect:78 Painter is disconnected

Just for the record -- how to uninstall displaylink drivers on Ubuntu.

As root:

Code:

systemctl stop dlm

find /lib/modules -name evdi.ko | xargs rm -f

rm -rf /usr/src/evdi*

rm -rf /var/lib/dkms/evdi

rm -rf /opt/displaylink

rm -f /lib/systemd/system/dlm.service

(I am doing it for the sake of downgrading to answer if the old driver works with two monitors).

Status update:

1. I haven't succeeded in making the old driver (1.3.54) work.
2. After reinstalling the new driver (1.4.210), I got zero monitors.

I made it working after lots of trial-and-error. The culprit is to boot the machine with dock disconnected, then log in (i.e. start X session for your user), when plug in the dock. This way, both monitors work.

It still works with either zero or 1 monitor if I forget to unplug the dock when I'm booting the laptop. But at least I know a workaround.

I'm having the same issue on a Dell D6000 and a Latitude 7480.

It will disconnect (monitors go black) but the window manager still thinks they are there.

I have to disconnect the USB C cable, reconnect, then re-activate the monitors to get display out.

Also the instructions posted earlier in this thread to generate output files now 404's.