DisplayLink external DVI/VGA display WORKS! Now on to fine tuning it.

[Linux-SWAT]

I asked Notaz if it's possible to include the udlfb and dependencies in Zaxxon kernel, so it should help a lot here.

 

[Askarus]

That's great news.


Some questions:


1:


How do I end sessions?


When I plugg in my DisplayLink device screen (monitor) becomes green.


Then I type startx, screen becomes black for a short period of time and then I'm happy with full HD.


How do I go back to one screen mode on Pandora? Am I forced to reboot here?


2:


Is it possible to optimize DIsplaylink via software (driver, etc) to get better performance?


I don't want you to do this. It's simply for me to get some knowledge about that subject.

 

[hmc]

AWESOME


It works.


It's so amaying.


Full HD 1080x1920 out of my Pandora.

Congratulations!

Some Question:


How to change resoution?


I want to try lower resolution.


Maybe I'll get some performance boost (it's not that important but would be nice).

In theory this should be possible using a subsection "Display" in section "Screen", just as you find it already in the Pandora's xorg.conf for the OMAPFB screen:

Section "Screen"

     Identifier      "Screen0"

     Device          "OMAPFB"

     Monitor         "Monitor0"

     DefaultDepth    16

     SubSection "Display"

          Depth        16

          Modes "800x480"

     EndSubSection

EndSection

i.e. take the section containing "DisplayLinkScreen" stuff and insert such a subsection into it:

Section "Screen"

     Identifier      "DisplayLinkScreen"

     Device          "DisplayLinkDevice"

     Monitor         "DisplayLinkMonitor"

     DefaultDepth    16

     SubSection "Display"

          Depth        16

          Modes "1024x600"

     EndSubSection

EndSection

The "Modes" line allows to list several different modes, that can by cycled through with some keyboard shortcut (I don't remember which one. Was it [Ctrl]-[Alt]-[+] and [Ctrl]-[Alt]-[-] ?).


I cannot test it currently, but in theory this should work.

 

[Askarus]

Thanks.


Would be sooo great to see this on Zaxxon.

 

[hmc]

should be no problem at all, as soon as notaz included the kernel driver.

 

[Askarus]

as soon as notaz included the kernel driver

Notaz should include the kernel driver then :lol: .

 

[Linux-SWAT]

First he has to enable ext4load for uBoot ;^).

 

[hmc]

Step 3 (compiling the udlfb module from fresh sources) of the original post is not necessary, as compiling the kernel with the "udl" driver selected as a module already generates the udlfb module.


I edited the original post accordingly.

 

[Askarus]

Great.


As Step 2 is the one that took about 5 hours is it possible to make it also not necessary in further releases of Slackware. It's annoying to be forced to do for every new RC.


Are you still working on the fine tuning mentioned in you topic ?

 

[Linux-SWAT]

I'll wait for the next Zaxxon kernel.


Anyway, i'll probably release a custom kernel in my new release, and also xorg drivers.

 

[hmc]

I still have plans for fine tuning of course, but I don't have time for working on this currently.


It seems that real hotplug is not possible with the versions of X and udlfb (kernel):


http://superuser.com/questions/502359/is-it-possible-to-have-displaylink-usb-display-hotplugging-with-xorg-1-13-on-ker


What would in theory be possible using the hotplug mechanism of Linux, as I understand it, would be, to kill and restart X automatically on every plug / unplug of a DisplayLink device.


Of course, this is a really bad hack. Open applications would lose any unsaved data.


But I could think of a semi-automatic solution:


Whenever hot(un)plug of a DisplayLink adapter is detected, prompt the user to save any unsaved data, and to then hit the "Restart X" button of the prompting dialog.


What do you think?


Or do you have any better idea?

 

[Askarus]

Leave as it is.


If I start Zaxxon without Displaylink and insert the DL device I simply have to launch a terminal and type startx. Then I'm on the big screen.


When I logout then I' back on the small screen on my Pandora.


Some nice configuration menu would be more important for me.


To switch on the fly which screen is used and which resolution I want.

 

[hmc]

Askarus, wait a moment:


You have made DisplayLink work on Zaxxon? how did you do it? Just copy over the self-compiled SL4P kernel and modules? And then?


Also, the startx thing:


Do you basically start a second instance of X, that runs on the DisplayLink, or what do you do exactly?


Doesn't such a setup need two different configuration files then? One for the Pandora screen, and one for the DisplayLink device?

 

[hmc]

I have removed the tutorial from the first post of this thread and moved it into the Wiki now, so anyone can add improvements easily:


http://pandorawiki.org/Software_projects/OS/Slackware/Advanced_usage/USB_graphic#Display_Link


Also, I have edited the first post and added links to the Wiki article.

 

[Linux-SWAT]

Nice (and compliant) ;^).

 

[DAP]

It seems that real hotplug is not possible with the versions of X and udlfb (kernel): http://superuser.com...org-1-13-on-ker What would in theory be possible using the hotplug mechanism of Linux, as I understand it, would be, to kill and restart X automatically on every plug / unplug of a DisplayLink device.

Ubuntu seems to do hot-plugging. They may be restarting X because the existing screen goes black for a second or two when I hot-plug my second montor.


(I've been having to do this a lot due to a boot sequence timing issue causing my video to start in safe mode. I have to unplug my second monitor, reboot, login connect my second monitor, logout, and log back in to work around the bug).

 

[hmc]

thanks! this could be a start for investigation.

 

[Askarus]

No, no, no.


I didn't get it working on Zaxxon.


Stratx:


1: Start slackware


2: Wat until it's booted


3: Plug in DisplayLink


4: Open Terminal


5: Type "startx"


→ Big Display

 

[hmc]

oh, I thought, because you started with "If I start Zaxxon"...


Question: Step 2: Do you let it boot with or without X being started automatically (i.e. with or without prior editing of the default initdefault in /etc/inittab)?


If without, your procedure is the same as mine, however, step 4 "open a terminal" sounds like you first boot into x and then start another instance of x. This sounds interesting and I wonder how you do it. What xorg.conf do you use for that? The normal DisplayLink-enabled org.conf?


Oh, this would make sense, as that xorg.conf works well for both setups, with and without a DL adapter connected.

 

[ekianjo]

One question, what do you do with a Pandora displaying Full HD ? What applications make sense to use with it ? (browsing, I guess?)