Comment 60 for bug 292214

I have a G550 video-card and got the same error message after updating my debian-testing on 14 Sep 2009. To get the Xserver working again, I deleted the '/etc/X11/xorg.conf' and restarted the window-manager. After that, both screens were working again, but showing the same contents.
While searching for a solution I soon found this thread, but it took me one week of further investigation to get both screens back working as they done it before the update. Since I have Debian, not Ubuntu, none of the repositories here could help me, so I had to bite the bullet and build the driver from source with the patches from Andy MacLean. For other Debians who are stranded here with the same problem:

1.Load the source package from: <http://ftp.de.debian.org/debian/pool/main/x/xserver-xorg-video-mga/xserver-xorg-video-mga_1.4.11.dfsg.orig.tar.gz>
2.Extract the the file (tar -xzf).
3.cd into the directory as root.
4.'apt-get install xserver-xorg-dev libdrm-dev x11proto-xf86dri-dev x11proto-gl-dev libgl1-mesa-dev'
5.'./configure'
6.'make' (to see if the original can be compiled)
7.Edit the files 'mga_driver.c' and 'mga.h' on the basis of Andy's third patch. (I don't know if automatic patching would work, because of the different line-numbers in the source).
8.'make' (to build the new driver)
9.'cp /usr/lib/xorg/modules/drivers/mga_drv.so /usr/lib/xorg/modules/drivers/mga_drv.so.old' (as a precaution)
10.'cp src/.libs/mga_drv.so /usr/lib/xorg/modules/drivers' (Attention: the Xserver will automatically restart !!)
11. Both screens are working again :-)

Many thanks to Andy MacLean,

Wolfram