Help fixing csync output with video-ati

Arvid Brodin arvidb at
Wed Mar 17 15:52:24 PDT 2010

Hello list-dwellers!

I have a PAL TV hooked up via RGB to my graphics card. It needs
composite sync:

$ ./xrandr --newmode "960x576 at 50i" 18.479 960 991 1078 1183 576 592 601
625 interlace -csync

[+|-]csync is supported by the xrandr application, but not shown in
'xrandr --help' - also, all csync options just give +hsync +vsync
(checked with oscilloscope) - so my guess is part of the implementation
is missing.

I long for watching movies from my couch again, and so I would like to
fix this. :) I'm not asking for a bug fix/new feature, but rather I'm
looking at this as an opportunity to learn something of the inner
workings of X.

XRRCreateMode() is called to create the new mode, but I cannot step into
this function with gdb, and I haven't been able to find out where it is

If some nice developer could step me through this I would appreciate it
a lot! (I.e. give hints on how to continue, tell me why the function is
not "steppable", that it's no use, or whatever comes to mind. :) Perhaps
my question belongs on xorg-driver-ati at or
xorg at

I'm running:
X.Org X Server 1.6.5

$ xrandr --version
xrandr program version       1.3.2
Server reports RandR version 1.3

xf86-video-ati-6.12.4 on a Radeon HD 3870.

Arvid Brodin

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