Radeon 9600 Pro "true" DVI output only works under X11

[Yeechang Lee]

I have an Asus A7V133 motherboard-powered system with an ATI Radeon
9500 Pro. My Samsung Syncmaster 170T monitor supports both DVI and
analog VGA imput. It connects to the Radeon with the DVI cable that
came with the monitor. Using a botton on the monitor, I can choose
either the DVI or analog VGA signals that are simultaneously carried
over the DVI cable.

That's the theory, at least. However, when my (Linux) system boots,
the monitor only picks up the analog VGA signal over the DVI cable;
the monitor will display nothing in the "true" DVI mode. This is true
whether dealing with BIOS messages, Linux bootup messages (I use the
stock vesafb framebuffer), or virtual consoles. Only under X11 and its
ATI binary Linux qdrivers can I use either the VGA-over-DVI and true
DVI modes. I presume the ATI driver somehow turns the true DVI signals
on.

To be honest I can't really see a difference between the VGA-over-DVI
and true DVI pictures; both are slightly, but meaningfully, better
than the picture using the monitor's analog input. But I'd still like
to get the true DVI output working outside X11, if only with the Linux
virtual consoles. What am I missing?

 

[Ben Pope]

I have an Asus A7V133 motherboard-powered system with an ATI Radeon
9500 Pro. My Samsung Syncmaster 170T monitor supports both DVI and
analog VGA imput. It connects to the Radeon with the DVI cable that
came with the monitor. Using a botton on the monitor, I can choose
either the DVI or analog VGA signals that are simultaneously carried
over the DVI cable.

That's the theory, at least. However, when my (Linux) system boots,
the monitor only picks up the analog VGA signal over the DVI cable;
the monitor will display nothing in the "true" DVI mode. This is true
whether dealing with BIOS messages, Linux bootup messages (I use the
stock vesafb framebuffer), or virtual consoles. Only under X11 and its
ATI binary Linux qdrivers can I use either the VGA-over-DVI and true
DVI modes. I presume the ATI driver somehow turns the true DVI signals
on.

To be honest I can't really see a difference between the VGA-over-DVI
and true DVI pictures; both are slightly, but meaningfully, better
than the picture using the monitor's analog input. But I'd still like
to get the true DVI output working outside X11, if only with the Linux
virtual consoles. What am I missing?

I've never done this, but I'm assuming that it's distinctly more likely that
you can enable such functionality with radeonfb?

Here's a fairly old post:
http://www.directfb.org/mailinglists/directfb-dev/2002/08-2002/msg00037.html

Oh and there's some info here that may or may not be relevant... gotta rush.

Ben