## Enabling Randr12 support in nouveau
Randr 1.2 is used by Nouveau. No need to explicitly enable it, and you cannot disable it.
## Generic HowTos
* Simple step-by-step guide to create a very clean Randr12-based config file with all old junk removed:
* [[http://wiki.debian.org/XStrikeForce/HowToRandR12|http://wiki.debian.org/XStrikeForce/HowToRandR12]]
* Very nice illustrations but lots of examples which you'll not apply to Nouveau, like TV output support:
* [[http://www.thinkwiki.org/wiki/Xorg_RandR_1.2|http://www.thinkwiki.org/wiki/Xorg_RandR_1.2]]
## Dual Head setup
### xorg.conf
#### Sections and configuration settings to remove
Randr 1.2 does not use multiple Screen sections, so if you have those you have to remove them from your xorg.conf :
* If you have two sections like these, remove one of these sections (in this example Screen1):
Section "Screen"
Identifier "Screen0"
...
Section "Screen" <==== Remove this second section, if you have sone (start removing lines here)
Identifier "Screen1"
...
EndSection (stop removing lines here)
* If you have a Option "MonitorLayout" or/and "Screen" options in the Device section, remove them
* Also remove the second Screen entry from the ServerLayout section. Example :
Screen 0 "Screen0" 1680 0
Screen 1 "Screen1" LeftOf "Screen0" <= remove this one (for Screen1)
* Also remove any RightOf/LeftOf indications from the remaining Screen line in the ServerLayout section (see above)
#### Settings on xorg.conf for Randr12
Note that with today's software you often don't need a xorg.conf file at all for nouveau and dual-head to work.
If you do not preconfigure a left/right/above/below setup in your xorg.xonf (see next section) add `Virtual x y` to your Display Section:
[[!format txt """
Section "Screen"
Identifier "Your Screen identifier here"
DefaultDepth 24
SubSection "Display"
Depth 24
Virtual 3360 1050
EndSubSection
Device "Your Device identifier here"
EndSection
"""]]
The example above configures a framebuffer for two monitors, each using resolutions up to 1680x1050 pixels, put side-by-side dynamically, after you started X. The values are calculated like this:
Virtual
Only the part which the monitors show is used: You can start and use X with one monitor as ususal but later add a new monitor and use `xrandr` with `--leftof` or `--rightof` to place the new monitor left or right of your primary monitor.
#### Preconfigured side-by-side (LeftOf/RightOf) setup thru xorg.conf
If you have done the above, you can also preconfigure the two monitors to be side-by-side right from the X startup. With this, you do not even need the "Virtual " line because then, the X server already knows before starting that it has to allocate a virtual framebuffer which fits both Monitors side-by-side.
You need to make the following changes for this to work (simplest way):
* Change the Monitor identifiers in your xorg.conf to the identifiers which "xrandr" reports and add a LeftOf/RightOf to one of the Monitor sections. Example:
Section "Monitor"
Identifier "DVI-D-0"
...
Section "Monitor"
Identifier "VGA-0"
...
Option "LeftOf" "DVI-D-0"
Then restart X and enjoy :-)
## Examples for the usage of the Xorg xrandr tool to manipulate the monitor setup
Usage: `xrandr -h` gives a short list of available options, `man xrandr` shows you the xrandr manual.
When Randr12 is enabled, you can check the current Randr12 configuration with with `xrandr -q` (or no options):
[[!format txt """
xrandr -q
Screen 0: minimum 320 x 200, current 2960 x 1050, maximum 3000 x 1050
DVI-A-0 disconnected (normal left inverted right x axis y axis)
DVI-D-0 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
1680x1050 60.0*+
1280x1024 75.0 59.9
1280x960 59.9
1152x864 75.0 74.8
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 75.0 72.8 66.7 60.0
720x400 70.1
VGA-0 connected 1280x1024+1680+0 (normal left inverted right x axis y axis) 350mm x 262mm
1280x1024 84.8* 75.0
1152x864 75.0
1024x768 84.9 75.1 70.1 60.0 59.9 43.5
832x624 74.6
800x600 84.9 72.2 75.0 60.3 56.2
640x480 84.6 75.0 72.8 74.8 66.7 60.0
720x405 69.6
720x400 87.8 70.1
"""]]
Change the mode of an output using:
[[!format txt """
xrandr --output