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

[Tzafrir Cohen]

On Fri, Dec 02, 2011 at 05:56:31PM +0000, James Simmons wrote:
> 
> > 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?

Yes.

> 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.

That's what I have. Anything that can be done to help with KMS?

> 
> > 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. 
> 

The system locks up completely. How will a debug version help? Even a
remote ssh session is hung.

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