Re: [Linux-fbdev-devel] Re: [lkml]Re: [lkml]Re: Matrox G400 Dualhead

[Petr Vandrovec]

James Simmons wrote:
> >A very neat trick. X can now be ended correctly. Unfortunately, any
> >scrolling on any VT afterwards gives me a corrupted screen - parts of
> >the screen from other VT's are inserted below, or over the cursor
> >position, and at 'half-line' intervals. In typing this email, I've seen
> >it 5 times already.
> >I'm willing to test anything - but the corruption is alway gone after I
> >switch VT's. So getting a screendump is not easy.
> 
> I never have seen this problem before. Petr do you know what it could be?

If you are still running X with enabled DRI, then it is known problem.
When
DRI is enabled in X, mga driver randomly reprograms some Matrox
acceleration
registers (color depth, screen width, byte ordering) - so you must use
same depth and resolution in both X and on console if you are using DRI.
I believe that it is problem which thunder7 sees. I never got reported
that
matroxfb just decided itself in the middle of screen to do something
else,
it was always tracked to X running on (invisible) background, but still
playing with accelerator.
								Petr

P.S.: You can try 'fbset -accel false', but fixing X is better.
Unfortunately,
nobody cares...