Disable screen blanking on VT switch

[Dave Airlie]

On Sat, Jan 17, 2009 at 3:19 PM, Connor Behan <connor.behan at gmail.com> wrote:
> I have two video cards each hooked up to a different monitor. The AGP
> card driving my laptop screen is the boot display device which shows the
> console and I've configred xorg to use the PCI card driving my external
> monitor when I start it. I can use Ctrl+Alt+Fn to switch between X on
> the big screen and a ttyn on the small screen but whenever I do so, the
> inactive screen is not surprisingly blank. I'd like to be able to see X
> persist on my external monitor when a text console is in the foreground
> and eventually to see the output of a background tty on my laptop screen
> when tty7 is in the foreground.
>
> I know the second direction sounds harder... people have been asking
> questions about it since 2002 and the only solutions I've seen have been
> unstable kernel patches that are now dead. But I am naive enough to
> think that X could be configured to not blank the screen even when its
> own console is switched away from. After all, it's still running. Do you
> know of a way to do this? I've tried all combinations of tty and vt
> related arguments to X but haven't got it to work yet.
>
> One thing that I think might work, is initializing a framebuffer for
> both cards and then using con2fb to move a particular console to the
> other framebuffer before starting X. I can't try this however because
> all framebuffer drivers I've tried only create a framebuffer device for
> the primary AGP card. So do you know how to disable screen blanking when
> switching VTs or how to use multiple monitors with a framebuffer driver?
> Thanks alot.

X at least with normal drivers can't do this, there is only one VT and
when X is switched
all the screens it controls go away, you can't do text mode and X at
the same time on multiiple cards
with the current system AFAIK.

fbdev might be an option but again I'm not sure, you'd need to avoid
the VT switch in X, using
(sharevts or novtswitch type options).

Dave.