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

[Alex Deucher]

On Fri, May 16, 2008 at 10:16 AM, Francois Gouget <fgouget at free.fr> wrote:
> On Fri, 16 May 2008, Alex Deucher wrote:
>  [...]
>  > 1920x1200 is probably a bit much for your card bandwidth-wise.
>
>  Sure, this graphics card is pretty old and not very powerful. However:
>   * I used it to drive the VGA output in 1920x1440x75Hz for 7 years with
>    my 21" CRT.
>   * About 6 months ago I switched to an LCD screen and used it to drive
>    the DVI output at 1920x1200x60Hz without trouble.
>   * It's only last wednesday when I upgraded that the DVI output stopped
>    working at all.
>   * I have since downgraded the driver to and I'm using the DVI output in
>    1920x1200x60Hz (as confirmed by both xrandr 1.1 and my LCD screen).
>

The the driver was substantially rewritten for xrandr 1.2 support.
The mode handling has changed a lot.

>  So it's not a hardware problem.
>
>
>  > Do lower resolutions work ok?  (1680x1050 or 1024x768) You might try
>  > reducing your color depth to 16 bits.
>
>  I thought about an issue with the single-link DVI bandwidth limit too.
>  So I tried 1600x1200x60Hz and 1024x768x60Hz and neither worked. I did
>  not try 16 bits mode.
>
>
>  > 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
>
>  I will try this tonight. Do these correspond to driver settings that
>  changed between 6.6.3 and 6.8.0?

The DefaultTMDSPLL is new, but the default behavior should be the
same.  displaypriority exists in both versions.

Alex