I'm running Debian Jessie on a laptop as a server, and interact with it exclusively through SSH. Since I never need to interact with it, I just leave it sit at a TTY to save resources, and turn the screen off with
vbetool. This was working just fine, until I installed
firmware-linux-nonfree to fix the following boot error.
[ 10.048681] [drm:radeon_pci_probe] *ERROR* radeon kernel modesetting for R600 or later requires firmware-linux-nonfree.
After installing the non-free firmware, vbetool now has absolutely no effect on turning my screen on or off. Since there's no X running on it, and I would prefer it to stay that way, I can't turn the screen off through some more conventional means such as
Why exactly did installing the non-free firmware break
vbetool from working, and is there any way that I can get it working again? Alternatively, if there isn't a way to get
vbetool to work again, is there a different way that I can disable the screen without using
Edit: I should qualify, that I'm not looking to just blank the screen, but actually kill the backlight as well so the whole screen is off. The laptop is pretty old already, and I'm looking to save what little time I have left on the screen.