How to configure radeonsi for clone mode?

[Alex Deucher]

On Fri, Jan 2, 2015 at 5:25 AM, Boszormenyi Zoltan <zboszor at pr.hu> wrote:
> Hi,
>
> for an NVIDIA based Xorg setup with the proprietary driver,
> I have this file as /etc/X11/xorg.conf.d/nvidia.conf:
>
> Section "Device"
>         Identifier      "NVIDIA"
>         Driver          "nvidia"
>         Option          "AutoServerLayout" "on"
> EndSection
>
> Section "Screen"
>         Identifier      "Screen0"
>         Option          "TwinView" "on"
>         Option          "TwinViewOrientation" "Clone"
>         Option          "AutoServerLayout" "on"
> EndSection
>
> I would like to know how to setup the "clone mode" using the
> radeon driver on a Zotac ZBOX NANO-AQ01 which uses the
> radeonsi driver and has HDMI-0 and DisplayPort-0 connectors
> according Xorg.0.log.
>
> I came up with this using "man xorg.conf":
>
> Section "Monitor"
>     Identifier    "HDMI-0"
>     Option        "AutoServerLayout" "on"
>     Option        "Position" "0 0"
> EndSection
>
> Section "Monitor"
>     Identifier    "DisplayPort-0"
>     Option        "AutoServerLayout" "on"
>     Option        "Position" "0 0"
> EndSection
>
> Section "Device"
>     Identifier    "RADEON"
>     Driver        "radeon"
>     Option        "AutoServerLayout" "on"
>     Option        "Monitor-HDMI-0" "HDMI-0"
>     Option        "Monitor-DisplayPort-0" "DisplayPort-0"
> EndSection
>
> However, there is a small problem. I have connected a HD-ready
> capable TV using a HDMI-DisplayPort converted to the DisplayPort
> connector (native resolution 1366x768) and a FullHD capable
> monitor using the HDMI connector. The result doesn't look good
> and confirmed by Xorg.0.log:
>
> [2853811.002] (II) RADEON(0): Output DisplayPort-0 using initial mode 1360x768 +0+0
> [2853811.002] (II) RADEON(0): Output HDMI-0 using initial mode 1280x800 +0+0
>
> If I connect the FullHD-capable monitor to the DisplayPort,
> the result is more satisfying:
>
> [2854212.540] (II) RADEON(0): Output DisplayPort-0 using initial mode 1920x1080 +0+0
> [2854212.540] (II) RADEON(0): Output HDMI-0 using initial mode 1920x1080 +0+0
>
> How can I setup clone mode in a way using the xorg.conf.d
> extension file to make the system recognize the best resolution
> and use that instead of limiting it to the monitor capabilities
> connected to DisplayPort? It seems it's the primary connector.
>

FWIW, static xrandr configuration is not driver specific for the open
source drivers.  It should work the same regardless of what driver you
are using.  You'll want to take a look at the xorg.conf man page.
You'll probably want to play with the following options:


       Option "Primary" "bool"
              This optional entry specifies that the monitor should be
treated  as  the  primary  monitor.  (RandR
              1.2-supporting drivers only)

       Option "PreferredMode" "name"
              This  optional  entry  specifies  a  mode to be marked
as the preferred initial mode of the monitor.
              (RandR 1.2-supporting drivers only)

Alex