evdi and Kernel v7.1 - any chance to get this working any time soon?

[godfatherjohn]

I would like to update my Kernel to v7.1 and I really rely on evdi.

Any chance to get this to work with Kernel version 7.1 ?

[richgieg]

I just tested with kernel 7.1 on a RHEL 10.2 system. The evdi module (v1.14.16) built successfully using DKMS and all my monitors are working via my Wavlink dock. Are you seeing a particular error / issue?

[godfatherjohn]

@richgieg - Thanks for that info. I had 0.15.0 installed (Linux Mint 22.2). When I installed kernel v7.x (while being on 6.17) I got a dkms error message. I have a simple WaveLink Dual USB-A-to-4K adapter.

[richgieg]

@godfatherjohn What was the DKMS error message?

[richgieg]

@godfatherjohn, are you still having the issue?

I tested on Linux Mint 22.2, upgrading from kernel 6.17 to 7.1, with this version of the driver installed:

Release Notes: https://www.synaptics.com/sites/default/files/release_notes/2026-06/DisplayLink%20USB%20Graphics%20Software%20for%20Ubuntu6.3-Release%20Notes.txt

Download: https://www.synaptics.com/products/displaylink-usb-graphics-software-ubuntu-63?filetype=exe

The DKMS autoinstall for evdi succeeded during the upgrade to kernel 7.1:

richard@mint222:~/repos/linux$ sudo make install
[sudo] password for richard:                 
  INSTALL /boot
run-parts: executing /etc/kernel/postinst.d/dkms 7.1.0 /boot/vmlinuz-7.1.0
 * dkms: running auto installation service for kernel 7.1.0
Sign command: /usr/bin/kmodsign
Signing key: /var/lib/shim-signed/mok/MOK.priv
Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der

Building module:
Cleaning build area...
make -j12 KERNELRELEASE=7.1.0 all INCLUDEDIR=/lib/modules/7.1.0/build/include KVERSION=7.1.0 DKMS_BUILD=1....
Signing module /var/lib/dkms/evdi/1.14.16/build/evdi.ko
Cleaning build area...

evdi.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/7.1.0/updates/dkms/
depmod....
dkms autoinstall on 7.1.0/x86_64 succeeded for evdi
 * dkms: autoinstall for kernel 7.1.0                                                                         [ OK ]

[godfatherjohn]

Hi there. I don't have access to my workstation right now and unfortunately won't until mid-September (I'm travelling).

I was using Mainline for the kernel update from 6.17 to 7.1.

Here is the complete Mainline log. This also includes the v4l2loopback module, which I then managed to fix manually.

mainline 1.4.14

install 7.1 

Downloading 7.1

Installing 7.1                                                        

Selecting previously unselected package linux-headers-7.1.0-070100-generic.

(Reading database ... 1005449 files and directories currently installed.)

Preparing to unpack .../linux-headers-7.1.0-070100-generic_7.1.0-070100.202606141628_amd64.deb ...

Unpacking linux-headers-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

Selecting previously unselected package linux-headers-7.1.0-070100.

Preparing to unpack .../linux-headers-7.1.0-070100_7.1.0-070100.202606141628_all.deb ...

Unpacking linux-headers-7.1.0-070100 (7.1.0-070100.202606141628) ...

Selecting previously unselected package linux-image-unsigned-7.1.0-070100-generic.

Preparing to unpack .../linux-image-unsigned-7.1.0-070100-generic_7.1.0-070100.202606141628_amd64.deb ...

Unpacking linux-image-unsigned-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

Selecting previously unselected package linux-modules-7.1.0-070100-generic.

Preparing to unpack .../linux-modules-7.1.0-070100-generic_7.1.0-070100.202606141628_amd64.deb ...

Unpacking linux-modules-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

Setting up linux-headers-7.1.0-070100 (7.1.0-070100.202606141628) ...

Setting up linux-modules-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

Setting up linux-headers-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

/etc/kernel/header_postinst.d/dkms:

 * dkms: running auto installation service for kernel 7.1.0-070100-generic

Sign command: /usr/bin/kmodsign

Signing key: /var/lib/shim-signed/mok/MOK.priv

Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der



Building module:

Cleaning build area...

make -j24 KERNELRELEASE=7.1.0-070100-generic all INCLUDEDIR=/lib/modules/7.1.0-070100-generic/build/include KVERSION=7.1.0-070100-generic DKMS_BUILD=1...(bad exit status: 2)

Error! Bad return status for module build on kernel: 7.1.0-070100-generic (x86_64)

Consult /var/lib/dkms/evdi/1.14.16/build/make.log for more information.

Sign command: /usr/bin/kmodsign

Signing key: /var/lib/shim-signed/mok/MOK.priv

Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der



Building module:

Cleaning build area...

make -j24 KERNELRELEASE=7.1.0-070100-generic KERNEL_DIR=/lib/modules/7.1.0-070100-generic/build v4l2loopback...(bad exit status: 2)

Error! Bad return status for module build on kernel: 7.1.0-070100-generic (x86_64)

Consult /var/lib/dkms/v4l2loopback/0.15.0/build/make.log for more information.

dkms autoinstall on 7.1.0-070100-generic/x86_64 failed for evdi(10) v4l2loopback(10)

Error! One or more modules failed to install during autoinstall.

Refer to previous errors for more information.

 * dkms: autoinstall for kernel 7.1.0-070100-generic

   ...fail!

run-parts: /etc/kernel/header_postinst.d/dkms exited with return code 11

dpkg: error processing package linux-headers-7.1.0-070100-generic (--install):

 installed linux-headers-7.1.0-070100-generic package post-installation script subprocess returned error exit status 11

Setting up linux-image-unsigned-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

I: /boot/vmlinuz.old is now a symlink to vmlinuz-6.17.0-35-generic

I: /boot/initrd.img.old is now a symlink to initrd.img-6.17.0-35-generic

I: /boot/vmlinuz is now a symlink to vmlinuz-7.1.0-070100-generic

I: /boot/initrd.img is now a symlink to initrd.img-7.1.0-070100-generic

Processing triggers for linux-image-unsigned-7.1.0-070100-generic (7.1.0-070100.202606141628) ...

/etc/kernel/postinst.d/dkms:

 * dkms: running auto installation service for kernel 7.1.0-070100-generic

Sign command: /usr/bin/kmodsign

Signing key: /var/lib/shim-signed/mok/MOK.priv

Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der



Building module:

Cleaning build area...

make -j24 KERNELRELEASE=7.1.0-070100-generic all INCLUDEDIR=/lib/modules/7.1.0-070100-generic/build/include KVERSION=7.1.0-070100-generic DKMS_BUILD=1...(bad exit status: 2)

Error! Bad return status for module build on kernel: 7.1.0-070100-generic (x86_64)

Consult /var/lib/dkms/evdi/1.14.16/build/make.log for more information.

Sign command: /usr/bin/kmodsign

Signing key: /var/lib/shim-signed/mok/MOK.priv

Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der



Building module:

Cleaning build area...

make -j24 KERNELRELEASE=7.1.0-070100-generic KERNEL_DIR=/lib/modules/7.1.0-070100-generic/build v4l2loopback...(bad exit status: 2)

Error! Bad return status for module build on kernel: 7.1.0-070100-generic (x86_64)

Consult /var/lib/dkms/v4l2loopback/0.15.0/build/make.log for more information.

dkms autoinstall on 7.1.0-070100-generic/x86_64 failed for evdi(10) v4l2loopback(10)

Error! One or more modules failed to install during autoinstall.

Refer to previous errors for more information.

 * dkms: autoinstall for kernel 7.1.0-070100-generic

   ...fail!

run-parts: /etc/kernel/postinst.d/dkms exited with return code 11

dpkg: error processing package linux-image-unsigned-7.1.0-070100-generic (--install):

 installed linux-image-unsigned-7.1.0-070100-generic package post-installation script subprocess returned error exit status 11

Errors were encountered while processing:

 linux-headers-7.1.0-070100-generic

 linux-image-unsigned-7.1.0-070100-generic

mainline: done 

[richgieg]

Thank you for the info. Any chance you can provide the contents of the following file?
/var/lib/dkms/evdi/1.14.16/build/make.log

You mentioned you're traveling, so I'm guessing probably not, but I wanted to check just in case.

[godfatherjohn]

Hi again. ..I was just about to let you know that I currently can't supply you with

cat /var/lib/dkms/evdi/1.14.16/build/make.log

cat /var/lib/dkms/v4l2loopback/0.15.0/build/make.log

...a shame. ...Only in mid-September. ..I turned the machine off before I left.

[richgieg]

I was able to reproduce the issue. When using Mainline to install kernel 7.1, it's trying to use GCC v15 to build the DKMS modules, but Mint 22.2 has GCC v13. I was able to fix it by doing the following:

Uninstall kernel 7.1:

sudo mainline uninstall 7.1

Install GCC v15 (v13 will still be available as gcc -- v15 is installed as gcc-15):

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install gcc-15 g++-15

Install kernel 7.1:

sudo mainline install 7.1

Just out of curiosity, what was the fix for the v2l4loopback module?

[godfatherjohn]

Oh, wow(!!), that is some great trouble shooting. ..About v4l2loopback, I can't tell what the exact error was. I remember that I 'manually' removed the kernel module (rmmod) and then I had to clean up the dkms versions (sudo apt remove v4l2loopback-dkms and sudo rm -rf /lib/modules/$(uname -r)/updates/dkms/v4l2loopback.ko.zst and sudo depmod -a) for the system to pick up that version 0.15.3 was installed (make ...).

If you still have Linux Mint running, it might be possible to quickly install v4l2loopback and then trying to update the kernel to 7.1 (from 6.17) using Mainline. I would assume that the error is cropping up again.

[sirzooro]

Ubuntu 24 LTS has switched from kernel 6.17.0-40 to 7.0.0-28 about week ago. Unfortunately it still uses gcc 13 by default and driver build fails. Default repos (including ones from Ubuntu Pro subscription) also do not contain gcc-15 (only up to gcc-14), so one would have to add non-standard repo in order to install gcc-15. What is worse, on my laptop it somehow created broken boot image (it cannot be mounted or something like this). Fortunately I am still able to choose previous working kernel from boot menu.

[richgieg]

@sirzooro I tried to reproduce the issue by doing the following:

• Install fresh Ubuntu 24 LTS running 6.17.0-40 kernel in a VM
• sudo apt update
• sudo apt-mark hold linux-generic-hwe-24.04 to ensure kernel is not upgraded yet
• sudo apt upgrade
• Install latest official DisplayLink Ubuntu driver from:
  • https://www.synaptics.com/products/displaylink-usb-graphics-software-ubuntu-63?filetype=exe
• Reboot
• lsmod | grep evdi to verify evdi module is loaded
• sudo apt-mark unhold linux-generic-hwe-24.04 to allow kernel to be upgraded
• sudo apt update
• sudo apt upgrade to install the 7.0.0-28 kernel

I was expecting it to fail, but the DKMS build of evdi succeeded even though only GCC 13 is installed.

After looking into it further, I remembered that the issue that @godfatherjohn was running into is that the kernel they were trying to install via mainline was built with GCC 15, so DKMS was trying to find GCC 15 on their system to build evdi.

The 7.0.0-28 kernel for Ubuntu was built with GCC 13, therefore DKMS should be using GCC 13 to build evdi, so I think you might be experiencing a different issue:

$ cat /proc/version
Linux version 7.0.0-28-generic (buildd@lcy02-amd64-004) (x86_64-linux-gnu-gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0, GNU ld (GNU Binutils for Ubuntu) 2.42) #28~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jul  1 15:50:57 UTC 2

If you run this, what evdi version is shown?
ls /var/lib/dkms/evdi | grep "^1."

[sirzooro]

Thanks. I had version 6.2.0 installed. Looks that synaptics-repository-keyring.deb file which I downloaded about year ago from https://www.synaptics.com/products/displaylink-graphics/downloads/ubuntu for some reason did not allow apt to download new version. I have downloaded new keyring file and after this apt updated displaylink-driver to version 6.3.0. New driver compiles successfully.