Triple monitor, one card; xrandr => xorg.conf

[Nick Urbanik]

Dear Folks,

On 26/05/13 08:52 +1000, Nick Urbanik wrote:
>Sorry, perhaps I have been insufficiently clear on what my aim is.
>
>1. If you look at the xrandr command (which, as I said, works like a
>   charm), you will see that I want to put the DisplayPort-0 in the
>   middle, the DVI-0 on the left, the VGA-0 on the right.
>
>2. Automatic configuration works just fine, with DisplayPort-0 on the
>   left, DVI-0 in the middle, VGA-0 on the right.  But I don't want
>   that order, because the DisplayPort-0 monitor is new and fabulous,
>   while the other two monitors are old and not so good.
>
>3. I am trying to make the xorg.conf do what the xrandr command does,
>   when X starts up.
>
>Perhaps I need to specify that the DVI-0 should be on the left?

Making a tiny amount of progress: with this configuration, X can start
(a nice change from some previous attempts!), and lightdm shows the
screens in the correct order!  Hooray!

But when I log in, the behaviour is rather odd; the VGA appears on the
left; the DisplayPort is next, with the DVI mirroring the DisplayPort.
My xrandr command gets it back into the desired state and order.  But
I still wish that I could achieve the same result with xorg.conf as
with the xrandr command, right from the beginning.

Advice most welcome.

Section "ServerLayout"
    Identifier "home"
    Screen "left-screen" 0 0
    Screen "middle-screen" RightOf "left-screen"
    Screen "right-screen"  RightOf "middle-screen"
EndSection

Section "Device"
    Identifier "ati-5450"
    #Screen 0
    #Screen 1
    #Screen 2
    Option "Monitor-DVI-0" "left"
    Option "Monitor-DisplayPort-0" "middle"
    Option "Monitor-VGA-0" "right"
    #BusID "PCI:01:00.0"
    Driver     "radeon"
EndSection

Section "Screen"
    Identifier "left-screen"
    Device "ati-5450"
    Monitor "left"
EndSection

Section "Screen"
    Identifier "middle-screen"
    Device "ati-5450"
    Monitor "middle"
EndSection

Section "Screen"
    Identifier "right-screen"
    Device "ati-5450"
    Monitor "right"
EndSection

Section "Monitor"
    Identifier "left"
    Option "LeftOf" "DisplayPort-0"
EndSection

Section "Monitor"
    Identifier "middle"
    Option "RightOf" "DVI-0"
EndSection

Section "Monitor"
    Identifier "right"
    Option "RightOf" "DisplayPort-0"
EndSection
-- 
Nick Urbanik             http://nicku.org           nicku at nicku.org
GPG: 7FFA CDC7 5A77 0558 DC7A 790A 16DF EC5B BB9D 2C24 ID: BB9D2C24