Xorg / radeon / vesa ignoring custom ModeLines bug?

Roland Scheidegger sroland at tungstengraphics.com
Thu Mar 8 04:16:48 PST 2007

José Oliver Segura wrote:
> [...] (II) RADEON(0): Total number of valid DDC mode(s) found: 0 (II)
> RADEON(0): Valid mode using on-chip RMX: 1024x768-Over (II)
> RADEON(0): Total number of valid FP mode(s) found: 1 (--) RADEON(0):
> Virtual size is 1024x768 (pitch 1024) (**) RADEON(0): *Mode
> "1024x768-Over": 65.0 MHz (scaled from 0.0 MHz), 48.4 kHz, 60.0 Hz 
> (II) RADEON(0): Modeline "1024x768-Over"   65.00  1024 1040 1176 1344
>  768 770 776 806 [...]
> (5) Why is the driver ignoring that ModeLine? After *lots* of 
> googling, I've tried to force the driver to ignore any automatic 
> configuration possibility, like EDID or DDC:
Because you're using LCD/DFP. The driver will ignore all custom
modelines no matter what, and always use on-chip scaler (rmx) to scale
all other resolutions to that. Even without ddc/edid data, it will get
panel timing parameters from bios.
That said, the proper solution would be to program the 2nd dac correctly
for tv-out, atitvout is a gross hack you can't really expect to work.
If you don't need the panel, maybe you could convince the driver to just
set up the primaray dac for a crt panel (with MonitorLayout "CRT,
NONE"), thus accepting all modelines, though I'm not sure this will work.


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