> since 26th of February I have problems with the DisplayPort outputs
> of my Lenovo ThinkPad T470p. If I use the notebooks output I can get
> one external monitor to function but daisy chaining does not work. If
> I use the output of the docking station, the external monitors do not
> work at all.
It could be driver error, Xorg error or misconfiguration.
I'd start with checking "$ xrandr" output.
>
> At boot, betwenen GRUB and disk encryption, there is a error message
> that reads relevant:
>
> [drm:drm_dp_send_link_address [drm_kms_helper]] *ERROR* Sending
> link address failed with -5
Sounds like a video driver issue. It may be related to your problem or not.
If you are using Intel video, then drivers are part of the kernel.
And for Nvidia there is a separate package (AFAIK)