Kernel 4.7: Edid length too small
 

Hello, I'm using a DisplayLink with the kernel 4.7, as soon as I plug the device and try to start my X server it crashes with the folowwing error:

Here is my EDID, as per /var/log/displaylink:

I appreciate any help (or directions) you guys can give me, I have some experience in programming and debugging, so I can give more information if necessary.

This is odd - the EDID is indeed too short. Could you attach all logs, gathered with our Linux Support Tool?

Regards,
Michal

Here it is, hope it helps.

Update: I tested with a different monitor, still not working, the error message appears to be different tho.

Thanks,

We can reproduce the issue with your original monitor. We should be able to fix it.
As for the other attempt, there are no signs of loading evdi kernel module at all in dmesg?

Regards,
Michal

You are right Michal.

I probably had unloaded it for being able to start X server.

That's good news. The two displays are from LG, and they are very similar, despite their sizes, maybe the problem is related.

I'm sending the files again. Please let me know if you need anything else.

Best regards.

I got the same error about EDID. Attached my edid information. Please note that the external monitor was working before I switched from ubuntu 16.04 to 16.10.
Now my pc crashes if I plug the docking station in. I have the latest driver installed

Update: so far we've narrowed down the problem to be specific to Intel+NVIDIA systems using nouveau, running Ubuntu 16.10.

Cheers,
Michal

Same problem here
 

It was working on ubuntu 16.04 not on 16.10.
I had some problems with my laptop and 16.04 that's why I switched to 16.10 (kernel 4.8.0-26-generic).

I have two monitors: Dell U2415 and Dell P2314H.
And the same problem with both.

Laptop: Acer Aspire VN7-591G, BIOS V1.13 01/08/2015

Thanks Michal!

Is this related to the opensource part of the driver (evdi)? If so, I can spend some time investigating, if there are any "How to contribute" or "How to debug" page, that would be even better :)

Yes, I am pretty sure it would be reproducible with any evdi client on such systems.

About contributing - thank you for the offer.
In fact, I have just published a very simple client for evdi - completely unrelated to DisplayLink hardware - but with full source code, with an intention to show how evdi can be used. Hopefully this can make some reproductions and diagnostics easier (as I am certain you could reproduce most, if not all, issues with such client, too)

https://github.com/mlukaszek/evdipp

Cheers,
Michal

Hi,

I also get this error.

Laptop: Asus UX303UB, Kubuntu 16.10, Nvidia/Intel graphics.
USB screen: Asus MB169B+

Thanks!

Any news?
 

It's been a while, just wanted to know if there are any news about this problem.

Have a great week!

I understand based on the earlier discussion it sounds like this is an EVDI problem? Is there a better place for us to track this(bug report or gitlab issue) so I know when I can look at updating *buntu on my laptop?

I also have this issue with Linux Mint 18.2 Kernel 4.4.0. on Dell M3800 Intel+NVidia

Confirming EDID lockup after idle period 4.15.0-34-generic/ 18.04 LTS bionic
 

In a multimonitor setup where the displaylink 5500 usb is attached, after an idle period of some hours, the log fills with tens of thousands of
evdi: [E] evdi_painter_connect:529 Edid length too small

All screens appear dark but active (blanked, not 'sleep' or 'off'). The only remedy is to reboot - but it is possible to get a console window to do a soft-reboot. The processor is:

Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz. The system is a Dell XPS 8910 MB 1.1.7 latest bios. The native HD graphics 530 v6 controls two monitors. An GM107 / Nvidia geforce gtx 750 Ti rev a2 controls three monitors. The Diamond displaylink controls one. The nvidia uses the nouveau driver.

The only other abnormal symptom is:

During normal operations, from time to time when using the USB mouse I see vertically elongated rectangle damage, perhaps 30 pixels wide and 150 tall, usually white, with a normal gap of maybe 80 pixels atop another rectangle, repeated perhaps 4 or 5 times in a vertical stripe of sorts. As the mouse moves that description of vertical screen damage gets repainted perhaps every 300 horizontal pixels as the mouse moves on the intel-chip controlled monitors. Not on the display link monitor when it works, nor the nvidia controller monitors. The screen buffer damage can be repaired by dragging any window across the damaged area.

So, I'm guessing the evdi driver in response to usb activity decides to write on the memory space used by the intel graphics chip.

Back to the displaylink evdi complaint:

Here's a fairly typical example of the onset of the problem. The system was unattended for some hours at that point:

...
Sep 21 19:03:11 homenx systemd[1]: Started Run anacron jobs.
Sep 21 19:03:11 homenx anacron[12786]: Anacron 2.3 started on 2018-09-21
Sep 21 19:03:11 homenx anacron[12786]: Normal exit (0 jobs run)
Sep 21 19:03:15 homenx kernel: [16331.484410] evdi: [E] evdi_painter_connect:529 Edid length too small
Sep 21 19:03:15 homenx kernel: [16331.484412] evdi: [E] evdi_painter_connect:529 Edid length too small
... x multiple tens of thousands...
The monitor is a Dell 1907FP.

The way to recover was to press numlock, then ctl-alt-F1, F2.. This would temporarily flash the tty console before reblanking all the monitors. After attempting to re-connect to the GUI tty (which would display nothing but a solid cursor line), the following attempt to tty0 would not blank. The evdi controlled monitor would be black, the rest would display a normal console tty0, and a log-in would work normally. Lightdm /lxde/lubuntu was crashed at that point. Console operations were normal.

I tried it with the 4.2.29 driver native. I downloaded the git version, set it up with dkms, same thing. I signed it and rebooted with the secure boot, same thing. The monitor controlled by the display link is a dell at 1280x1024 resolution. DVI-I-2-2 connected 1280x1024+2960+1076 (normal left inverted right x axis y axis) 376mm x 301mm 1280x1024 60.02*+ 75.02

support tool output attached
 

FYI, support tool output is attached.

FWIW, I moved the displaylink adapter from a USB 3 port to a USB 2 port. We'll see if that matters during the next day or two.

Same problem when plugged in the USB 2 port. It worked normally for longer, but this morning it was the same symptom. It does appear related to a period of idleness. Not being able to unblank? Though the system power settings were to only blank the screen, not enter into any suspend or sleep state.

Is anyone at DisplayLink reading this?

This happens to me with the latest DisplayLink version, with a Lenovo P1 Gen2 and a Thunderbolt 3 Workstation Dock, with Ubuntu 20.04. Latest BIOS/firmware/everything.

I cannot log into the GNOME desktop, unless I disconnect the dock. If I reconnect it, only one external display is used.

Previously, prior to update to the latest firmware, this did not happen.