Re: Next round of console patches

Vladimir Dergachev (vladimid@blue.seas.upenn.edu)
Tue, 1 Sep 1998 21:50:35 -0400 (EDT)

> >
> > card, base_register, length
>
> OK, I now see what you're driving at. I haven't looked closely at the
> FB code, but I had assume that mtrr_add() was called "safely"
> (i.e. for framebuffer RAM only and not for MMIO registers). I guess
> that's not the case?
> So the PCI bus addresses that the FB code finds may well contain MMIO
> registers?
> What's the story with cards that would be safe to make the FB
> write-combining? Do they only have their registers in a separate
> region? I would have thought that this is generally how it's done with
> PCI cards?

A good portion of cards map their IO registers in the end of the memory
aperture. Since the idea of fb is to use VESA call to create the aperture
and then _dont use_ any registers at all (bc then we would have to know
what is the specific card we are running) there is no way (apriori) to
know where we have legal framebuffer space and where we have MMIO
registers

Vladimir Dergachev

>
> Regards,
>
> Richard....
>
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