Mint 21.3 does not see HDMI port behind Acodot docking station.

[ThomasAn]

(This is more like a report, than a request for help).

Out of the box, Mint 21.3 (Runing the 6.5 kernel and the 535 nvidia driver. Was the same with the 5.15 stock kernel) will not see the HDMI port behind the Acodot USB 3.0 docking station.
This laptop has been running windows 10 with no issue in this regard (the Linux dual boot is only recent)

When I install the Display-Link drivers, then the monitor works properly ... but other things break (eg, it takes 4min to boot. Things that were fine before all of a sudden need troubleshooting). So I gave up on this.

You can get it to boot a little faster by masking the offended service, but then a couple of other services become bottlenecks, so it's not worth it.

Code: Select all

sudo systemctl mask systemd-udev-settle.service

https://www.synaptics.com/products/disp ... ads/ubuntu
https://support.displaylink.com/knowled ... les/684649

[SMG]

... will not see the HDMI port behind the Acodot USB 3.0 docking station.

What does that mean? What is a port behind a docking station? Like a supplemental port of some type?

When I install the Display-Link drivers, then the monitor works properly ... but other things break (eg, it takes 4min to boot. Things that were fine before all of a sudden need troubleshooting).

The issue with Displaylink 5.8 and slow boot time is known. Use the fix in this topic [SOLVED]Displaylink errors causing 2 minute freeze at boot (the part in red in the first post) to fix slow boot time.

[ThomasAn]

What does that mean? What is a port behind a docking station? Like a supplemental port of some type?

The dock itself has a physical HDMI port on it.
Anything connected to that port is not visible to Mint 21.3, as in the monitor is not detected. It stays black. No signal.
It magically comes to life the moment DisplayLink is installed. (although I was told Display Link should not be necessary).

Thanks for pointing out the other thread about the long boot times.
It only happens with Display Link installed (which I have now uninstalled) and the monitor is currently hooked directly to the laptop. Once I get some time will take a look (although, I'd rather not be doing micro-surgeries like that. If it makes it stop calling systemd-udev-settle, it'd be equivalent to masking the service, as I tried, but may still end up with the other bottlenecks. Will see.)

[SMG]

The dock itself has a physical HDMI port on it.
Anything connected to that port is not visible to Mint 21.3, as in the monitor is not detected. It stays black. No signal.
It magically comes to life the moment DisplayLink is installed. (although I was told Display Link should not be necessary).

Is this the dock?
(It says Linux is not supported, but that may be because it needs the DisplayLink driver?)

[ThomasAn]

Yeah, that's the one.

I started this topic as a post-it note; possibly even for others that might be using the same dock. Especially in view of videos like this claiming that Display Link is entirely unnecessary and Linux systems know how to interface with docks 100% of the time. That's a channel with 600K subscribers, so a lot of people will be seeing that video and some might come here with this issue.

https://youtu.be/xsdFNpThetE?t=1141

[SMG]

Especially in view of videos like this claiming that Display Link is entirely unnecessary and Linux systems know how to interface with docks 100% of the time.

Having helped people install DisplayLinkk drivers for several years now (including the workarounds needed for different bugs) there are definitely docks which require DisplayLink drivers. There is now a PPA which makes installing the driver easier than it had been in the past. There is also a DisplayLink user forum for getting help.

However, many docks do not require DisplayLink drivers. One has to check the specs to know if a dock does or does not require the driver.