Sometimes graphics unresponsive

[trepseq]

Hello!

Today I got my new USB-DVI-Adapter with a Displaylink inside (HP NL571AA). After a couple of trials I found that my ubuntu 16.04 loads drivers for the adapter differently, in this ways:

a) Wait for boot up of computer, then connect the displaylink-adapter:

$ lsmod | grep udl
udl 32768 0
drm_kms_helper 147456 3 udl,i915,evdi
drm 364544 12 udl,i915,evdi,drm_kms_helper
$ lsmod | grep evdi
evdi 40960 2
drm_kms_helper 147456 3 udl,i915,evdi
syscopyarea 16384 2 evdi,drm_kms_helper
sysfillrect 16384 2 evdi,drm_kms_helper
sysimgblt 16384 2 evdi,drm_kms_helper
drm 364544 12 udl,i915,evdi,drm_kms_helper
Case a) results in the same responsiveness of mouse and graphical elements as when not using the adapter --> very good! Thank you for this adapter!

b) Connect the adapter with computer off, then start the computer:

$ lsmod | grep udl
udl 32768 1
drm_kms_helper 147456 3 udl,i915,evdi
drm 364544 10 udl,i915,evdi,drm_kms_helper
$ lsmod | grep evdi
evdi 40960 0
drm_kms_helper 147456 3 udl,i915,evdi
syscopyarea 16384 2 evdi,drm_kms_helper
sysfillrect 16384 2 evdi,drm_kms_helper
sysimgblt 16384 2 evdi,drm_kms_helper
drm 364544 10 udl,i915,evdi,drm_kms_helper

Case b) results in kind of a stucking responsiveness of mouse and graphical elements. Animations and mouse pointer run slower and not fluently. This happens only under this ciscumstances:
- I have a picture as desktop background
- the monitor connected to the displaylink-adapter is not fully covered by windows, so that parts of the picture can be seen.
If I choose a solid color background, the behaviour of b) is the same as a) (so everything is fine). If I maximize a window on the monitor connected to the displaylink-adapter, the behaviour of b) is also the same as a).

Unplugging the adapter in case b) results also in a crash of my X session, so I have to login again.
If I then disconnect the adapter and unload the module udl
sudo rmmod udl
and then reconnect the adapter again, these modules are loaded:
$ lsmod | grep udl
udl 32768 0
drm_kms_helper 147456 3 udl,i915,evdi
drm 364544 9 udl,i915,evdi,drm_kms_helper
$ lsmod | grep evdi
evdi 40960 2
drm_kms_helper 147456 3 udl,i915,evdi
syscopyarea 16384 2 evdi,drm_kms_helper
sysfillrect 16384 2 evdi,drm_kms_helper
sysimgblt 16384 2 evdi,drm_kms_helper
drm 364544 9 udl,i915,evdi,drm_kms_helper
Then the graphics and mouse pointer of the computer behave like in case a).

My question is: How can I make b) behave like a) without all the trouble?

I'm using ubuntu 16.04 with up-to-date packages and your driver in version 1.1.62.

Thank you for your help!

[mlukaszek]

Try blacklisting udl module, so it's never loaded.

Cheers,
Michal

[trepseq]

Maaaan!! I need your brain!!

$ echo blacklist udl > /etc/modprobe.d/blacklist-displaylink.conf
$ update-initramfs -u
$ reboot

$ lsmod | grep udl
$ lsmod | grep evdi
evdi 40960 2
drm_kms_helper 147456 2 i915,evdi
syscopyarea 16384 2 evdi,drm_kms_helper
sysfillrect 16384 2 evdi,drm_kms_helper
sysimgblt 16384 2 evdi,drm_kms_helper
drm 364544 9 i915,evdi,drm_kms_helper

First I was going to write: DOH!! Of course I tried that already!
Then I tried again, this time with the update-initramfs.

It works! Everything on warp 10 again :-)

Thank you very much!