With bug#14611 fixed, now we can start X without monitor connected. But this only works if monitor disconnected before kernel booting.
If we disconnect monitor after kernel booting, the kernel still stores EDID info, and when start X, it considers EDID available so not accepting default modes, resulting no valid modes available and fail to start.
Created attachment 33544 [details]
Setting kernel command line "video=VGA-1:e" works, though "video=VGA-1:1024x768" still doesn't.
With this workaround I don't think this bug impacts users much.
Now the corresponding patch is already picked up by Dave.
Author: Zhao Yakui <email@example.com>
Date: Thu Mar 4 08:25:55 2010 +0000
drm: remove the EDID blob stored in the EDID property when it is disconnected
So this bug will be marked as resolved.
It works ok. Verified.
on Jan 19, 2017 at 10:42:33.
(provided by the Example extension).