Am 01.08.2012 15:42, schrieb Henri Verbeet:
On 30 July 2012 22:05, <s...@das-labor.org> wrote:
As far as I understood CRTC 0 is disabled, because it is only
capable of
generating analog video signals. I'm using a HDMI monitor, which is
controlled by CRTC 1. To use multihead (not clone), you have to
connect a
analog (VGA) and digital monitor (in my case). Each monitor will use
one
CRTC and each CRTC will show a different part of the same screen.
With this
in mind every active CRTC should be listed as "native Windows
monitor".
Mostly for reference, what driver are you using? Have you explicitly
configured a primary display at all (either through the xorg.conf
"Primary" option for the monitor, or with the xrandr utility), or is
it just picking up the first display connector and incorrectly
assuming it's connected?
I'm using ATI driver with xorg.conf but there's no "Primary" option.
I investigated some time and found the problem:
xrandr reports 0 outputs on the first disabled crtc, but there is a
"connected" outputs that block this crtc.
Connected means that it is plugged in weather or not it is powered or
in use.
This is why xrandr connects my "primary" monitor to crtc 1.
After unplugging all other monitors crtc 0 is used.
This example shows that with xrandr 1.2 multi-head support is
necessary.
To introduce multihead support every CRTC that has "connected" primary
outputs should be seen as display-device.
Since Windows is aware of disabled display-devices this should be no
problem.
EnumDisplayDevices should return all this CRTCs and let the application
decide which to choose.
Regards,
Patrick
