Hotkey Switching of Display Devices

[kjetilk]

I'm setting up my Compal HGL30 laptop for use in presentations.

It has a Geforce Go 7600, and what I'd like to do is set it up with hotkey switching, so that I can just press a key, and get the same picture on the projector. The system is now running driver version 169.12, it is a Ubuntu Hardy system. If I remember correctly, Twinview and hotkey switching used to be mutually exclusive options, but from the current documentation it seems to use TwinView.

However, the typical TwinView use case, with one big screen, is not want I want. I want to see the same thing on my screen as my audience sees on the projector, and I want to be able to turn it on without restarting X. The projector I use now has a resolution of 1024x768, so I think I'll start out with getting that to work. The documentation is a bit terse for me, has anybody got this working, and is able to share a xorg config?

[kjetilk]

I got a little further now, the nvidia-settings utility was actually very useful.

So, I did get a TwinView clone now, so I can show stuff on both screens.

However, this seems set the projector on permanently, i.e. I can't actually toggle it (I have to restart the X server, which is a pain). From the documentation, it sounds like what the hotkey switch does is to loop the list of modes in the metamodes. Thus I figured that if I set

  Option         "metamodes" "CRT: NULL, DFP: 1280x800 +0+0; CRT: nvidia-auto-select +0+0, DFP: 1280x800 +0+0; CRT: nvidia-auto-select +0+0, DFP: NULL"

Then the first mode would be nothing on the projector, laptop screen only. Then, when I first hit the hotkey, it would display both. Finally, if I hit it another time, it would display only the projector.

The first mode is indeed selected:

(II) NVIDIA(0): Setting mode "CRT:NULL,DFP:1280x800+0+0"

And my laptop screen is working. If I hit the hotkey switching button, I get the following line in my log:

(II) PM Event received: Capability Changed

but there is nothing to indicates it changes mode, and the projector never displays anything.

Is the toggling possible to achieve?

[kjetilk]

I tried this on a Dell Precision M65 with a Quadro FX 350M, with the same result, so it is not just the hardware on this one box. Any further ideas?

[kjetilk]

I've scrambled a little more in the blind about this, the main annoyance now is that I have to restart X.

It would be nice to just know if either of these options are true:

1) Hotkey switching does not work, restarting X is necessary.
2) Hotkey switching works with a more recent driver.
3) Hotkey switching works with 169.12, more digging is required.

[Tortus]

Have you tried using an almost empty xorg.conf and xrandr?

xrandr --output vga --auto --mode 1024x768

or something like that should work fine. Put that in a nice little script which runs some combinations of parameters depending on previous xrandr-output.
Finally, make your script run on hotkey and done.

Unfortunately i dont have any secondary output devices here to try the above on my desktop-pc and my laptop does not have nvidia graphics, but i dont see why this would not work.

[kjetilk]

Originally Posted by Tortus

Have you tried using an almost empty xorg.conf and xrandr?

Oh, cool! No, I wasn't aware I could use randr for this. But I couldn't get it to work, xrandr showed no other device, even if I had both screens running...

Then I found this, which seems to imply that randr 1.2 is not in the driver, and that is what I would need to have for this to work, right?