ati xrandr: cannot find crtc for output DVI-0

[Alex Deucher]

On 8/27/07, Jan Dittmer <jdi at l4x.org> wrote:
> Alex Deucher wrote:
> > On 8/27/07, Jan Dittmer <jdi at l4x.org> wrote:
> >> Given ati driver 6.7.192 and libxrandr 1.2.1 (Debian experimental)
> >> I cannot enable the DVI-0 output using:
> >>
> >> $ xrandr --output DVI-0 --right-of VGA-0 --mode 1280x1024 --rate 60
> >> xrandr: cannot find crtc for output DVI-0
> >>
>
> [old xrandr output snipped]
>
> > radeons only have two crtcs and you are trying to enable more an two
> > monitors.  you'll need to turn off S-video in order to turn DVI on.
> >
> > xrandr --output S-video --off
> > xrandr --output DVI-0 --auto
>
> Thanks for the quick reply. That indeed fixes the issue.
>
> > If you don't have a tv plugged in than I'm guessing you probably have
> > an analog monitor on DVI-0 which is causing the tv to detect load (TV
> > and DVI port share the same dac).
>
> Exactly. I've a dvi-vga adapter on the DVI port. With a DVI cable the
> color temperatures of the monitors don't match (under windows).
>
> A serious problem remains: The screen attached to the DVI output
> is a lot brighter. All the aliased stuff around glyphs gets white so that
> the screen is barely readable. All bright colors look white. Is this a problem
> with some gamma processing? (I checked the monitor settings more than twice,
> it's not correctable by lowering it's brightness or contrast)

Hmmm... I haven't seen this myself, but I does remind me of a similar
problem we had years ago, that may have resurfaced with all the
refactoring of the driver.  I'll see if I can dig up what the solution
was.

Alex