Re: working multihead

[Miguel F. <mi...@ce...>]

   Humm, I'm not pretty sure of what is going on, I haven't read the 
original post(s) of this thread...

   I think Brad is right, the multihead with multiple instances of 
XFree86 in a Matrox G400 should only be possible by using 
framebuffer interface. But as I have never been able to use fb with 
my hardware I haven't thought of this before. I wrote in the article 
that it should NOT work with boards like that.

   BTW, I may have removed something important for framebuffer 
from the init routines. If you want to use it please check for any 
mistakes the patch might have. Any updates on this issue are 
greatly appreciated...

Regards,

Miguel Freitas


On 24 Jan 01, at 19:18, Petr Vandrovec wrote:

> On 24 Jan 01 at 18:14, Brad Midgley wrote:
> > http://cambuca.ldhs.cetuc.puc-rio.br/multiuser/
> > 
> > he asks out loud but i'm pretty sure it wouldn't work with a card like a
> > dual-head matrox since two instances of X couldn't coordinate access to
> > the card. that's why the kernel would need to provide a framebuffer
> > interface to each screen (and demonstrates why we really need solid
> > kernel support for doing this properly)
> 
> If it does not work with dualhead G400, then he did something wrong:
> 
> (...)
> 
> If his driver tries to drive /dev/fb1 with matrox accelerated driver, it
> is for sure wrong - fb1 clearly says that there is no acceleration for
> this head. And each head returns 8MB (well, 7.9 and 8) of non-overlapping
> memory, so I do not see any problem here too.
> 
> Only problem which can arise is that fb1 supports 16/32bpp only, while fb0
> supports text/8/16/24/32. But it is again X/Xinerama problem, not fb
> one...
> 
> Or do I miss something?
>                                     Best regards,
>                                      Petr Vandrovec
>                                      van...@vc...
>