[PATCH] vga-sync-fields 0.0.8

Thomas Hilber xorg at toh.cx
Mon Sep 8 04:58:08 PDT 2008

If you ever wished to synchronize your VGA timing to an external signal source
like a DVB stream, this patch collection could be interesting for you.

It implements a kind of soft-PLL locking on the external signal. The VCO is
represented by dynamically adjusted VGA frame rate aka video timing.

Video timing is dynamically altered by temporary changing the contents of
HORIZONTAL_TOTAL register from within DRM-modules vsync interrupt routine.
This works fine for Radeon type (pre-avivo) graphics hardware. For further
information about compatible hardware see README. 

I also will try to port the patches to other hardware like Intel graphics.
There already is included experimental code for this.

The main application of the patch collection is probably a HTPC.

The newest patch 'vga-sync-fields-0.0.8.tgz' is available at


Have fun

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