Tim wrote:
Frode Petersen:
Btw, have anyone else got a xorg.conf with no entries in sections
'files' and 'modules'?
Tim:
I don't even have those sections. Defaults are presumed without them.
Frode Petersen:
This makes me a bit confused. Are all the entries that used to go here
assumed to be default settings, or are they dropped for different
technologies?
It seems that more defaults are presumed, and a fair bit of
auto-configuring each boot. That latter's caused me problems, when I've
turned on a system with the monitor un-powered. When turned on, I had a
generic 800x600 display, instead of the prior 1280x1084. And I kept on
getting the same issue with a monitor that it didn't have in its
database, until I preset it with more details.
After playing around over the last few days, this appears to be a
minimal configuration set up by Fedora:
# Xorg configuration created by system-config-display
Section "ServerLayout"
Identifier "single head configuration"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
EndSection
Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
EndSection
Section "Device"
Identifier "Videocard0"
Driver "nv"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Videocard0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
About the only specific thing in it was the "nv" driver. It beats me
why a keyboard ought to be part of the X configuration, though I do see
reason behind configuring a mouse in there. It's struck me for quite
some time that the mouse port ought to be part of the graphic card, more
than anything else. Let *it* work out where the pointer is, in
hardware.
Most xorg and commercial drivers try to determine the best values to
set by querying the monitor itself when the driver starts.
This method ignores any setting you have specified for resolution.
So you don't need a detailed xorg.conf any more for most monitors, but
on the other hand, the default behavior of querying the monitor is not
optimal in every instance.
The protocol and dataset are called 'EDID'. If your monitor responds to
an EDID request then most current drivers will do what the EDID data
suggests.
Look in your /var/log/Xorg.0.log for the string 'EDID'.
A few lines below that you will see something like:
Virtual size is NNNNxNNNN
NNNNxNNNN is the resolution that the monitor recommended. That is what
will be used unless you turn that feature off.
When such a driver is started in 'headless' mode, it will always assume
VGA (800x600) because that is the minimum allowed resolution for
standard VGA (all PC type monitors are supposed to be VGA compatible).
If you specify:
HorizSync 15.0 - 150.0
VertRefresh 48.0 - 190.0
ModeLine "1920x1080i" 82.620 1920 2089 2153 2448 1080 1100 1105 1125
+Hsync +Vsync interlace
in your xorg.conf, the EDID will not be used.
Figuring out what those values need to be is a topic in itself.
