From: James Simmons <jsimmons@edgeglobal.com>
  To  : andreas.beck@ggi-project.org
  Date: Mon, 8 Feb 1999 13:53:32 -0500 (EST)

Re: [linux-fbdev] Accel or not accel in kernel! (fwd)

On Sun, 7 Feb 1999 becka@rz.uni-duesseldorf.de wrote:

> Hi !
> 
> > Actually their is only one /dev/gfx. Its a smart driver. The driver
> > figures which card its on 
> 
> How should it ? Excuse me, if that's a dumb question, but ...

Actually you can do that in the kernel. You have to grap the current
console number and use that data to find which fb device is attached to
the console. I use something similar to make sure you can only open the fb
device that the VC your currently.

> > Only one fb is open and that is for the X server. 
> 
> Well - one should as well virtualize that, as Linux has VTs.
> IRIX has not, so this is a non-issue there.

Of course. /dev/gfx might be independent from the VTs. We are thinking
about this.

> What I don't like about the model is, that you'll have to interlock /dev/fb*
> stuff and /dev/gfx stuff, what seems to cause overhead.

Yes. I have a fb lock funtion taht locsk the framebuffer when you try to
use the accel engine. It also locks the framebuffer under other important
conditions.