Virtual screen sizes no longer working in radeon.

[Thomas Richter]

Hi folks,

due to my profession, I often have to work with larger images and use, 
for this reason, an oversized desktop on a regular sized monitor. Up to 
the 6.6.x driver series (? I hope ?) this worked correctly with the 
following configuration:

Section "Screen"
   DefaultDepth 24
    SubSection "Display"
     Depth      24
     Modes      "1280x1024"
     ViewPort 1280 1024
     Virtual 2560 2048    # <--- this here
   EndSubSection
   Device       "Device[0]"
   Identifier   "Screen[0]"
   Monitor      "Monitor[0]"
EndSection

This gives me a screen of 2560x2048 pixels I can scroll around in. 
Exactly what I need.

Unfortunately, not any longer as of 6.9.0. The above options simply do 
nothing useful at all. The screen stays the size it is.

xrandr seems like a solution, as

xrandr --fb 2560x2048

gives me a frame buffer the right size, but: it doesn't scroll anymore 
if I hit the boundary of the screen. Alas, it's unusable.

Thus, my questions:

o) Any hope for a fix of this?
o) As it seems, old versions of the driver like this chipset o.k., so 
any chance getting an older version to compile on this machine?

Before you ask: No, getting a better supported graphics card is not an 
option. This is a desktop workplace at a university, and installing new 
hardware there is a major hassle as it has to go through the administration.

Thanks,
	Thomas