Comment 19 for bug 107711

One root cause of inability to find a proper X resolution is a flaky EDID transfer from the BIOS. This is due to code added to vm86.c to try and resolve noisy error messages from the auditing subsystem. This is not an issue on non-x86 systems which use the x86emu code instead of vm86 to talk to the BIOS of the ATI card.

The definitive symptom here is if the EDID hex output in Xorg.0.log is missing, or mostly zeros.

The definitive work-around until the vm86.c kernel bug is fixed, or a more clever approach to getting the EDID data is added to the X server, is to add the line:

        Option "Int10Backend" "x86emu"

to the ServerLayout section of xorg.conf.