First post, by sdz
A bit of a weird question, but I'm trying to get 1920x1080p DVI output out of the VSA 100.
If a resolution above 1600x1200 is set, the image looks weird. At first I thought it's a limitation of the TMDS encoder used on these cards, SIL164, which states UXGA as the maximum resolution.
I replaced the SIL164 with the "PIN COMPATIBLE" TFP410 endoder (which does 1920x1080p just fine), and the image looks exactly the same. After that I checked the actual video output, and every time the horizontal resolution is greated than 1600 pixels, it just halves the output.
example:
if 1920x1080p is set, it internally renders at 1920x1080, the VGA outputs 1920x1080, the DVI outputs 960x1080.
Setting a resolution that results in a bandwidth lower than 1600x1200, but has more than 1600 horizontal resolution, results in the same behaviour, the horizontal output is halved.
If the Napalm databook is to be believed, the VSA 100 has a 12bit DDR 100MHz data bus to the TMDS encoder, which should be enough for 1920x1080p.
I also spent a couple of hours looking at the driver source code, but could not find anything relevant as of yet.
The only possible relevant thing I've found so far is this:
Maybe this scaling bit is related.
Any clues/hints?
