On Mon, 4 Oct 1999, Jos Hulzink wrote:
> On Fri, 1 Oct 1999, James Simmons wrote:
>
> > By the way the semaphore idea isn't a bad idea. The big things is we have
> > to make sure only one process at a time is using the framebuffer or accel
> > engine. Basically one process hogs the whole card.
>
> You are right, but what if this process dies while the framebuffer is
> locked ? I'm getting very afraid of becoming Microsoft compatible... (i.e
> the only way to leave a game is the reset-key)
>
> Just thinking.
Good point. Have to look at a way to handle this. I have started to
rewrite the schedular to handle this. I realized this is not a problem for
just video cards but really any device that has MMIO. On a SMP machine you
could have two processors access the MMIO at the same time causing the
card to go into a indetermined state. Also with some cards they might have
more than one MMIO area and each MMIO area thats accessed can effect the
card in such a way that the results you expected from another MMIO
region might not be what you want. Well I going to take this to the MM
guys to figure out away to handle this.
>
> Jos
>
