DVI-D SIGNAL NOT CLEAR WITH ATI X-300 and FRAME BUFFER DRIVER

[Alex Deucher]

On Thu, Sep 25, 2008 at 10:12 AM, Luigi Campora <luigi.campora at gmail.com> wrote:
> Hi everybody,
> I'm running Linux 2.6.21 radeonfb driver (rel. 2.0) on an ATI X300 sapphire.
> The produced DVI-D signal (on a 1600x1200x16 resolution) is not as clear as
> the one produced by WINXP in this way:
> pixel timing clock is OK and so is each data wire, but 0's and 1's falls
> outside regular DVI eye (I'm measuring with a
> 6GHz high-impedence diffrential probe).
>
> Lots of "buzzing" is produced on my HP montor when I use a 5m DVI-D cable:
> this does not happen under WIN XP.
>
> I'm afraid something is missing from the driver concerning signal (some
> hidden tuning?)
>
> Can someone help?

don't use radeonfb.  It was written mostly for old macs and hasn't
really seen updates in ages.  Support for newer (relatively) asics is
dodgy at best.  Your best bet is to use X or if you need a high res
console, vesafb or try the newer modesetting drm bits.

Alex