From: James Simmons <jsimmons@edgeglobal.com>
  To  : ggi-develop@eskimo.com
  Date: Thu, 12 Aug 1999 22:52:32 -0400 (EDT)

Re: GGI and XFree86 and stuff

> Before we get overly enthusiastic about PingPong and stuff:
> 
> The locking problem needs to be solved. If we go for an asynchronous
> acceleration subsystem, we have to properly lock access to the framebuffer.
> Not only on the application side, but as well in the linear-* libs.
> 
> To my knowledge Marcus has implemented that for the Matrox fbdev driver.
> We should have a look at that and make it generic.

I'm assuming this is for cards that can't have the framebuffer and accel
accessed at the same. I was thinking about this. I have rewritten the
fbdev system to be wrapper around accel functions instead of the old
fbcon-cfb* functions. Now the problem is if /dev/fb is mmapped. Kernel
side I can keep track of when the accel engine is busy/idle but I don't
know how to tell if someone is writing to the framebuffer itself. I will
take a look at marcus code this weekend to get some ideas. Any ides now
from you.