Ubuntu
xserver-xorg-video-ati package

  1. Bug #257941
  2. Comment #14

Comment 14 for bug 257941

Revision history for this message
Bryce Harrington (bryce) wrote : Re: [radeon] xorg gives black screen with external monitor connected through KVM-switch

Hi Rick,

Sorry it's taken so long to respond to this issue. Are you still experiencing it with the released Intrepid?

It sounds to me like the KVM is somehow corrupting the EDID data provided by the monitor. There are two useful tools for looking at the EDID information:

  xrandr --verbose

and, from the read-edid package:

  get-edid | parse-edid

I would suggest running each of these commands once with the monitor directly attached, and once with it through the KVM. See if there are any notable changes, and attach all the output from these commands.

Meanwhile as a workaround, you could also experiment with the IgnoreEDID or NoDDC options (see `man radeon`).