Bug#444223: xserver-xorg-video-ati: RS480 (radeon express X200G series): display goes to sleep after upgrade to latest unstable/sid

[Brice Goglin]

Alex Deucher wrote:
>> My monitor is connected to DVI-0, and a projector (which is currently
>> turned off) is connected to VGA-0.
>>
>>
>> The remaining problem was that with GDM I can see the display, but
>> after logging into GNOME when ConnectorCable is not set, display goes
>> blank; and I think I now understand why.
>>
>> I extract the most interesting part of the log.  My theory is that the
>> GNOME session tries to reconfigure xrandr such that it outputs to Port
>> 0, which is 'DVI-0' when ConnectorCable is set, and 'VGA-0' when it's
>> not set, and because xrandr doesn't quite know when VGA-0 is connected
>> or not, GNOME is able to set VGA-0 as the only output.
>>
>> Not quite sure if this is fixable
>
> gnome session seems to save arbitrary xrandr setups and I'm not sure
> how or when it does it.  I think there is a file you can delete that
> will leave the xserver as configured at start up.  Perhaps Brice
> knows?
>   

I asked our Gnome guys. The reply is below:

Yes, the GNOME session does indeed some RandR setup based on the
configured display properties, but only if the user has set them in
gnome-display-properties. I think it only tries to change the resolution
and refresh rate of the screen, and it doesn’t get the data through
RandR 1.2.

To delete this configuration, you can run:
  gconftool --recursive-unset /desktop/gnome/screen

Brice