Bug#481361: xserver-xorg-video-ati: No display on DVI output

[Alex Deucher]

On Thu, May 15, 2008 at 10:21 AM, Francois Gouget <fgouget at free.fr> wrote:
> Package: xserver-xorg-video-ati
>  Version: 1:6.8.0-1
>  Severity: important
>
>
>  Since the upgrade to 1:6.8.0-1 I cannot get the X server to work through
>  may ATI 7500 DVI output. More details:
>   * My ATI 7500 has three outputs:
>    - DVI
>    - S-Video
>    - VGA
>
>   * My LCD monitor (an iiyama B2403WS) has two inputs:
>    - HDMI + a DVI to HDMI cable
>    - VGA
>
>   * If I hook up the VGA output to the monitor, then the display goes
>    through the VGA output. However this results in a very ugly display
>    on my LCD monitor (dur to the digital->analog->digital roundtrip and
>    the high resolution) and is thus absolutely unusable.
>
>   * If I only hook up the DVI output, then the monitor displays an
>    all-blue screen for a bit and then enters power-save mode. This is
>    exactly the same thing that is happening if the monitor's DVI input
>    is not connected to anything. So this means the graphics card
>    is not putting out a signal (or nothing that's recognisable).
>
>   * Even when connected using the VGA cable, the monitor would sometimes
>    go black and repeatedly display a 'No signal' message. Moving the
>    mouse or using the keyboard did not get it out of that state. That last
>    issue might have been fixed by setting DPMS to off in xorg.conf.
>    It might be related to the DVI issue, but then maybe not.
>
>   * This issue seems a bit similar to bug 481084 except in my case it
>    happens after a cold boot and with a single display.
>    (so it's not a docking / suspend / multi-display issue)
>

1920x1200 is probably a bit much for your card bandwidth-wise.  Do
lower resolutions work ok?  (1680x1050 or 1024x768) You might try
reducing your color depth to 16 bits.  The following options may also
help:
Option "DefaultTMDSPLL" "TRUE"
Option "DisplayPriority" "HIGH"

If that doesn't help, try a modeline with a reduced refresh rate (50
hz rather than 60):
Modeline "1920x1200_50.00_rb"  127.75  1920 1968 2000 2080  1200 1203
1209 1229  +HSync -Vsync

Alex