Success! (was Re: External Monitor under Pismo)

Geert Uytterhoeven geert at
Sat May 5 00:14:36 EST 2001

On Fri, 4 May 2001, Sven LUTHER wrote:
> On Fri, May 04, 2001 at 03:57:29PM +0200, Benjamin Herrenschmidt wrote:
> > >> Note that if you don't want to mess with XFree, I recently added the
> > >> ability to control the CRT & LCD outputs of the Rage M3 to aty128fb in my
> > >> rsync tree. The tool to control it is on
> > >
> > >BTW, the recently released ibook is said to only have the capacity to mirror,
> > >not act as an independent display ? can that be or is it something limited in
> > >the mac drivers ? It has a 8MB embedded rage mobility 128, same as the
> > >titanium i think.
> >
> > Don't know. Note that the support I added to aty128fb uses one head only. It
> > just allow you to turn on/off the LCD and CRT output, but it's only mirroring.
> So mirroring will work, i guess.
> for dual head you will need X, isn't it, fbdev seems broken (well at least
> those using fbgen) for dualhead anyway. Don't know if aty128fb uses fbdev.
No, it doesn't.

> BTW, how does the rage 128 work, it has 1 accel engine that draws to the
> framebuffer memory, and one or more ramdac or digital out ports that send the
> fb data to the displays.

I think so.

If you point the second CRTC to the same frame buffer region, you'll have
mirrorring, else you have two different heads.

> So i suppose the you will need to use a trick similar to the matrox one to get
> dual headed accelerated X to work.

Yep. The same is true for atyfb (yes, I should add mirrorring/dualhead support
for the Mobility in my Vaio :-).

> But could it be possible to block this in hardware, and thus force mirroring
> only operation ?

I suppose yes.

> How many different rage 128 mobility are around anyway ?

No idea. I just at the ATI website earlier today, and they seem to have new
variants called M4 and Radeon Mobility.



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at

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

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