Re: [Linux-fbdev-devel] 3DFX mmio code to test with

[Geert U. <ge...@li...>]

On Fri, 3 May 2002, Ani Joshi wrote:
> Ah, it seems I never paid much attention to mmio and /dev/fb.  So is this
> the suggested use rather then /dev/mem?

Yes.

It also means that the fbdev layer can keep track off who is using its MMIO.
Note that you cannot (error -EINVAL) mmap MMIO if var.accel_flags is set, to
prevent conflicts between accel engine accesses between user space and the
fbdev.

> On Fri, 3 May 2002, Geert Uytterhoeven wrote:
> > On Thu, 2 May 2002, Ani Joshi wrote:
> > > After further looking at your code, it seems you are mmaping /dev/fb for
> > > your MMIO.  Is this even possible?  Shouldn't you be mapping /dev/mem?
> > > Has someone changed the fbdev layer so you can mmap mmio via /dev/fb?
> >
> > That change was made many years ago :-)
> >
> > You have the frame buffer at offset 0...fix.smem_len-1, and the MMIO at
> > fix.smem_len...fix.smem_len+fix.mmio_len-1.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@li...

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds