[R128 PPC] Apple Cinema Display black screen but no error

[Alex Deucher]

On Wed, Sep 10, 2008 at 6:46 AM, Flachy Joe <flachyjoe at hotmail.com> wrote:
> Hello,
> I try to use a Gentoo distrib on an Apple Cube G4 and a 22" Cinema Display
> (ADC plugged).
> The graphic card is an ATI Rage 128 PF/Pro AGP 4x TMDS.
> First the right resolution isn't autodetected but set it manualy to
> Xorg.conf is ok. (1600x1024 at 60Hz)
> Then, when I start the X server, I have a black screen, the monitor seam to
> sleep. Xorg report no error, it's just like all is good for it.
>
> Ideas ?

IIRC, the r128 driver still uses vbe for DDC which probably doesn't
work properly on ppc.  As to the blank display, it could be several
issues:
1. bad timing or pixel clock.  make sure you are using the proper
modeline for the monitor; it may require reduced blanking for example.
2.  Apple cinema displays tend to blank if the gpios used for ddc are
left in the wrong state.

Your best bet is probably to open a bug (https://bugs.freedesktop.org)
and attach your xorg log and config.

Alex