CVT reduced blanking.

[Benjamin Herrenschmidt]

On Tue, 2005-12-27 at 03:24 +0100, Luc Verhaegen wrote:

> DVI connected CRTs do exist. They're rare, but imho there's no reason 
> why they too can't be digitally connected.
> 
> This one is an iiyama vision master pro 453, (ha-901d). One analog 
> input, one DVI-D.
>
> Other CRTs which i know have DVI: IBM P260 and P275 and the NEC FP 
> 1375x.

All the IBM ones I have seen at work have a DVI connector that only
carries the analog signal. I yet have to see a single CRT that uses the
digital signals (I didn't say there is none, I'm just saying that it's
easy to be confused as it's a DVI connector but it only really carries
analog signaling in most cases).
 
> I don't know, i don't have even an analogly connected panel. If analog 
> panels handle reduced anyway, then it certainly shouldn't be disallowed 
> for them either.

Well, I would suggest for now that you provide a way (flag or whatever)
for the driver to inform the mode calculation stuff that it knows for
sure it's a digitally connected display (some have ways to detect it).
In absence of that, don't allow CVT unless it's explicitely enabled in
the config file.

Ben.