intel SDVO TV-out

Eric Anholt eric at
Wed Apr 2 16:35:16 PDT 2008

For those of you who have been desiring TV-out support over SDVO, I
pushed some code that should get us closer.  I'm trying to follow the
spec, but I'm not getting any output on my system.  I'm hampered by the
fact that the BIOS doesn't set up my card (so I don't have anything to
compare to), and that I've only got a lame LCD projector to output to
here (so if I've got bad timings, it won't give me anything different
from being disconnected).

The main weird part of SDVO TV-out I can see is that you're supposed to
set output timings appropriate to your format, but it's not specified
what the timings are for the various formats in the spec.  I also bet
that the preferred input timing commands will actually be supported and
relevant to getting it working, unlike on TMDS outputs.  That may be
troublesome for us, as preferred input timing is supposed to be done
after output timing is set, but we're supposed to have set adjusted_mode
(to be picked up for pipe programming) earlier in the process.

So, the code and register definitions are there for anyone to play with.
If you don't have the desire to hack on the code, but you've got SDVO TV
out working at the console, I'd love to see a Xorg.0.log log with
ModeDebug set in xorg.conf (and i830_dump_sdvo_regs() called in
i830_sdvo_init() for bonus points).

Eric Anholt                             anholt at
eric at                         eric.anholt at

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