Incomplete monitor specification data due to KVM switch interfering with EDID data collection

Please attach your /var/log/Xorg.0.log. The driver should get the right mode. Also, try Hardy alpha2 if it's better.

No reply, closing the bug. Getting the right mode should work in Hardy anyway, but if it doesn't feel free to reopen this.

This bug still exists in Hardy Heron.
qense@nott:~$ apt-cache policy xserver-xorg
xserver-xorg:
  Geïnstalleerd: 1:7.3+10ubuntu10
  Kandidaat: 1:7.3+10ubuntu10
  Versietabel:
 *** 1:7.3+10ubuntu10 0
        500 http://nl.archive.ubuntu.com hardy/main Packages
        100 /var/lib/dpkg/status
I'll add /var/log/Xorg.0.log in another reply since I can't add an attachment and reopen a bug at the same time. If you need any more information, please don't hesitate to ask. (I'm using the 64 bit version, my graphics card is an onboard geForce 6150.)

The xorg.log. Please keep in mind that I normally use a BenQ FP202W, which has no problems.

I attach the EDID here, maybe you can use it(although it's a .bin). I've set the resolution to 1400x1050 using nVidia's control centre(which I also used to acquire the EDID.

I confirm this bug still exists in Hardy Heron.

Attached please see the log you requested from a fresh install of Ubuntu 8.04 today.

To anyone trying to use this information in 8.04, please note that I had to update an additional section of /etc/X11/xorg.conf to get the expanded resolution selection:

Section "Screen"
 Identifier "Default Screen"
 Monitor "CPD-E200" #edit this line to use correct name
 Device "Configured Video Device"
EndSection

I did try this

Section "Screen"
 Identifier "Default Screen"
 Monitor "CPD-E200" #edit this line to use correct name
 Device "Configured Video Device"
EndSection

It did not work and I'm told its because 8.10 doesn't use Xorg fully

For anyone reading this issue, the cause has ultimately been determined to be the fact that a Belkin Omniview KVM switch interferes with the collection of EDID data for the monitor. There is no known solution to the EDID detection issue, which is a hardware problem outside of the control of any program.

As of version 8.10, the xorg.conf changes described above no longer work to allow the screen resolution to be set as desired. You can force a particular resolution by moving it to the start of the list of valid resolutions in xorg.conf, but you cannot change it during a particular session.

I am using Ubuntu 8.10, I applied those changes and the results havent
changed. I have read on several forums that the conf file is no longer being
actively utilized at boot.

Also I don't have a KVM switch, this is a stand alone 19" monitor.

sphacelate,

You might do the following to see if EDID detection is working correctly:

1) download the "read-edid" package from the repository ('sudo apt-get install read-edid')
2) check that EDID data can be captured from your monitor ('sudo get-edid | parse-edid')

If EDID data is captured correctly, you might look into opening a different bug report.

FactTech,

Well, the fact that KVM's sometimes squelch EDID has been a well known issue for a long long time. As you mentioned, there is no known solution that can be applied automatically. So for this particular issue I believe we're at a dead end.

However, for this use case, others have proposed that a solution would be to provide a manual configuration GUI such as we used to in Gutsy (displayconfig-gtk, which unfortunately became obsolete once X moved to xrandr). Do you agree that this would be an acceptable resolution for this particular problem? If so, then I'd suggest we dupe this bug to that master bug, bug #240916. Let me know if you agree; if not, explain what other resolution you'd like to see.

That sounds like a perfectly valid solution, Bryce. Thanks for following up.

I think that would be the second best solution, after fixing KVM.
But if it's as hard and nearly impossible as you said I think it would be better to include a GUI to manually change the resolution.