2.4b2 Forgets Display Positions

[dispnev]

So, I've been experimenting.

Apparently, OSX stores an arrangement for every combination of displays you have connected, and if OSX detects that you have monitors A, B, C connected, it will apply the ABC arrangement. If you add a monitor, say D, it will look for an arrangement setting for ABCD.

Apparently, what is happening on my system, and maybe everyone with this trouble, is that OSX is seeing a new Displaylink monitor or monitors, but is not getting the ID of the new monitor, so OSX just arranges them how it sees fit.

If I unplug one of my monitors, and replug it, my desired monitor arrangement comes back.

Why didn't it apply the saved arrangement when it boots? Apparently, it's getting the monitor IDs from Displaylink too late.

My guess is that simply delaying the connection of the DisplayLink monitors until the IDs are ready to give to OSX, could fix the problem. Or even just delay the whole process x (configurable) seconds.

I have an SSD, so parts of boot up may be way ahead of the USB devices. I wonder if booting on the old spinner might eliminate the problem too? I've spent too much time on this already to do that experiment though.

[Carlo]

Hi dispnev,

With the 2.4 workaround you should not be seeing the OS X bug that mixes up the monitors.
But there may be other reasons for a lost layout. For example problems in reading reliably the monitor's EDID or simply a bug in our SW.

Can you send to us the logs collected just after a wrong layout has come up?

The log tool is at http://www.displaylink.com/support/ticket.php?id=269
You can attach the logs here or send them through http://www.displaylink.com/support/ask_question.php

Thank you,
Carlo

[hitmusic100]

thank you so much dispnev and Carlo

I am having precisely the same problem with Yosemite forgetting my display arrangement after reboot . I have 3 monitors plus my MacBookPro inbuilt monitor. Am using this:

http://www.displaylink.com/shop/hot_...php#dell-d3100


Am using the latest Yosemite and Displaylink 2.4b1.

Please correct -I am wasting so much time arranging displays

Carlo - pls let me know what you need from me - thanks

[hitmusic100]

log attached (am using 3 displays as per photo: error occurs when switching from Lenovo T530 laptop to MacBookPro early 2011)

[ChristianP]

Hi hitmusic100,
unfortunately the logs don't show anything wrong. Screen seems correctly mapped to the same screen indexes/IDs.
Could you please try to reset display preferences running the following commands in a Terminal:

sudo rm -f /Library/Preferences/com.apple.windowserver.plist
sudo rm -f /Library/Preferences/com.apple.windowserver.plist.*
sudo rm -f /Library/Preferences/com.displaylink.plist
sudo rm -f /Library/Preferences/com.displaylink.plist.*
sudo rm -f /Library/Preferences/.GlobalPreferences.plist
sudo rm -f /Library/Preferences/.GlobalPreferences.plist.*
sudo rm -f /private/var/db/.com.apple.iokit.graphics
sudo rm -f /private/var/db/.com.apple.iokit.graphics.*

sudo rm -f ~/Library/Preferences/ByHost/com.apple.windowserver.*.plist
sudo rm -f ~/Library/Preferences/ByHost/com.apple.windowserver.*.plist.*
sudo rm -f ~/Library/Preferences/.GlobalPreferences.plist
sudo rm -f ~/Library/Preferences/.GlobalPreferences.plist.*
sudo rm -rf ~/Library/Preferences/Caches

Some files may not exist on your system.

After removing the files, reboot the machine and then connect the DisplayLink screens again, setting the desired layout. Grab the ~/Library/Preferences/ByHost/com.apple.windowserver.*.plist file.

Try to repro the issue (switching from the Lenovo laptop) and if the layout is not correct please grab again the ~/Library/Preferences/ByHost/com.apple.windowserver.*.plist file. I'd like to check the difference in your display preferences before and after the issue.

Since your problem happens after switching from the Lenovo laptop , which driver version are you using on that machine? The problem could be triggered by the firmware upgrade (though it's not a known problem).
Thanks!

[hitmusic100]

Thank you so much Christian for your help. I am using driver DisplayLink_7.7M4.exe on the Lenovo. (I had problems with the recent DisplayLink_7.8M0.exe driver). I will follow your instructions and reply - thanks again and regards, Darren

[dispnev]

Let me add that I have found that simply unplugging the USB of one of the displaylink monitors for a few seconds and plugging it back in sets everything back to the proper layout.

It appears that OSX remembers the layout you set based on the combination of monitors you have connected. If you have four monitors, ABCD, and lay them out, then unplug D, OSX will look for a saved layout for ABC, which is unrelated to the layout for ABCD. If you have only A and B connected, OSX will look for a monitor layout pattern defined for AB.

Understanding that, this is what I did. I unplugged the displaylink monitors, leaving the other 2. I set a monitor layout. I plugged in displaylink C and set a layout for ABC. I unplugged C and plugged in D and set a monitor layout for ABD. I plugged in C and set a monitor layout for ABCD.

My idea was that as the displaylink monitors are waking up, or getting detected, that it's either too fast for OSX, and it's still laying out AB, or ABC, or ABD, when it gets hit with the ABCD combo; or the monitor ID is changing as the monitor wakes up (from some generic name to the actual name).

In any case, and I'm not exactly sure why, doing this seems to have fixed it 90% of the time, and the other 10%, when the display is screwed up, I just unplug one of the displaylink monitors for a few seconds.

edit- let me add that it seems that the only time the monitors get screwed up anymore, is if I have booted the laptop away from my desk. If I boot at home and use my laptop as a laptop, then go back to work and plug it in and boot, it will probably be screwed up, and I'll have to unplug one of the DL monitors for a few seconds to get it back. I *THINK* that's when it happens.