image corruption when in multiseat mode and "vga!=normal" kernel parameter

Tomasz Chmielewski mangoo at
Thu Dec 18 04:18:39 PST 2008

Tomasz Chmielewski schrieb:
> I have a multiseat system with one AGP card (nvidia GeForce FX 5200; 
> "primary" card, BIOS displays here) and one PCI card (ATI), running Linux.

> If I start X in "multiseat mode" (X on both cards, two keyboards+mice), 
> image is corrupted on nvidia AGP card:

> The corruption happens with nv, nouveau and binary nvidia driver and a 
> vga= mode different than normal (i.e. vga=791).
> The corruption does _not_ happen when I don't use vga= parameter (or use 
> vga=normal).
> The corruption does not happen if I start X only on one of the cards.

I replaced the nvidia AGP card for an ATI card and I can see the same 

So it doesn't seem to be related to the graphics card or the driver, but 
some strange issue between the X server and Linux framebuffer?

Tomasz Chmielewski

More information about the xorg mailing list