Bug#547075: xserver-xorg-video-radeon: GL windows only work on 70% of screen area

Michel Dänzer daenzer at debian.org
Thu Sep 17 00:19:37 PDT 2009

On Wed, 2009-09-16 at 20:11 -0400, Eric Cooper wrote: 
> I have a dual-head setup as seen in xorg.conf below.  When using an
> OpenGL application like glxgears, or now gnome-games' sol-clutter, the
> app works fine anywhere on the VGA monitor, but only on the first 740
> or so pixels at the left of the DVI monitor.  Anywhere to the right of
> that results in garbage being displayed in that portion of the
> screen. I'm attaching a screenshot showing what happens when I move
> the window across this border.

This is a limitation between DRI1 (uses a single shared back buffer) and
the hardware (3D rendering limited to 2560x2560). It'll be fixed with
DRI2 (which will be available with KMS) because there each GLX window
has its own back buffer, so the hardware limit only applies to each
window separately.

Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer

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