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

[Francois Gouget]

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).

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?

-- 
Francois Gouget <fgouget at free.fr>              http://fgouget.free.fr/
                     Avoid the Gates of Hell - use Linux.