Reset PCI card

The symptom:

Sometimes, when I switch between virtual terminals, (away from X == tty7), instead of getting my usual login prompt, the picture I've had during my X session (or the picture of the display manager) stays on the screen, albeit with some of the colours screwed up (as if it were a 256 colour palette-based display, even though it's 24 bit colour - you know, like in Windows, when you have 256 colours and you switch from one app to another and the colours in your background picture get all frelled up). The terminal does switch over to the appropriate tty because I can log in and type whatever (blindly though) and it does work.

The problem:

There is no way to somehow reset my video card so that it once again switches between X and console mode correctly.

The question:

Is there any way of fooling an AGP card (or a PCI card) into believing that the computer has been powercycled/rebooted/whatever ? Alternatively, is there any other approach to fixing this problem (== getting my consoles back) ? I have no frame buffer devices compiled into the kernel (vanilla 2.4.18). This problem seems to be video card independent and it seems that starting multiple X servers tends to precipitate this problem. So far, I have experienced it with NVidia(AGP, has DRI), Voodoo5/5500(PCI, has DRI), ATI Rage Mobility P/M (AGP-Laptop, no DRI).
It's as if the video card all of a sudden refused to switch modes from 1024x768x24 to console and back.

The solution:
The only solution I could find (obviously unsatisfactory) is to reboot. Hence my question: I'd like to fool the card into thinking I've rebooted, or otherwise get it switching modes again.

Thanks for your attention.

Hi!

The "svgalib" has a tool named "reset_vga". It completely resets your VGA-card . You may try it... but it's only a workaround at the cause and not at the symptom.

I used it a longer time ago with a similar problem (only slightly similar - programmed the VGA-card "by hand", and needed to clear the scrambled output I produced :-) ).

ciao

Michael

That package doesn't have a nice automake/autconf installer, so I didn't run across the reset_vga thingy at first. I did, however, make it work with mode3:

1. SSH in
2. init 3
3. mode3
4. init 5
5. Close SSH
6. Walk over to the box
7. Log into all the text mode ttys (tty[1-6]), type "clear" and log out.

You're right though. This shouldn't be happening in the first place.

Thanks for all the help.