ATI Drivers report bogus dot_clock to xvidtune

[Roland Scheidegger]

Greg Stark wrote:
> When I ran xvidtune It reports the dot clock is 1976225.70Mhz. Of course
> that's wrong, my graphics card is not capable of driving a 1.9 petahertz
> signal...
> 
> I suspect this is the root cause of the problems I have and another user has
> reported with using mythtv with an ATI card. Since mythtv attempts to sync to
> the vertical refresh it gets *very* confused trying to match this refresh
> rate.
> 
> I'm not sure if this is a display bug in xvidtune or a bug in the driver so I
> wrote a little test program to print the output from XF86VidModeGetModeLine:
> 
> dot_clock: 1976225695
This looks like a driver bug. I have no idea though what driver you're 
talking about, there is no such thing as a ati driver (well there is 
technically, a driver wrapper which is called ati, but it doesn't do 
anyhting itself). So is this mach64? rage128? radeon? fglrx (take it to 
ati in that case)?
If that's radeon are you using mergedfb? It works just fine for me 
without mergedfb.
That said, I don't know why mythtv would need the pixel clock to sync to 
vblank, I'd think it's a pretty useless number for that.

Roland