[Openchrome-users] Sylvania (VX700) - black screen at 'modprobe viafb', problem resuming

[James Simmons]

> I'm not really sure if this is the right place, as I suspect my issues
> are on the kernel-level, but I figure this would be a good start.
> 
> I'm playing with a Sylvania netbook based on VIA C7-M CPU with a
> VX700-based display adapter (see lspci and such below). It originally
> had a system called gOS which I didn't really like. I installed Debian
> Testing on it. It is currently running an up-to-date system with the
> latest kernel from Debian Unstable. Though I also had similar issues
> with various other Debian kernels (2.6.32-5-686 from Stable, 2.6.32,
> 3.0) and with self-compiled 3.0.8 and 3.2.0-rc2.

Did you enable the "X server compatibility" for the viafb driver? If you 
enable that and it still doesn't work then your best bet is to just 
disable the vaifb driver. The xorg driver will work fine with UMS mode.
Also the DVI port is not supported at this time.

> When viafb is loaded the screen blacks-out immediately. If I disable
> loading it, I manage to get a display working. OpenChrome seems to be
> used in X. Not good enough for Gnome3, but it works.

That is due to the lack of OpenGL support :-( 

> However if I try to suspend and resume, the system resumes OK, but the
> display is messed up. pm-suspend --quirk-s3-bios seems to work around
> it.
> 
> Occasionally the system just hangs completely. I have no idea what makes
> it hang. I ran it with memtest86+ for a number of days and no problem
> was found. I see no aparant error message on the console. I tried
> running a network console a few times and got no useful output. 
> I'm really at loss on how to debug/fix this. 

Sounds like a GPU lockup. Usually this happens with the DMA engine.
First try with the viafb driver. If that doesn't work you can install the 
debug version of the xorg server and do a gdb backtrace of it.