02-25-2020, 07:02 PM
I don't know how to tell you how to undo the changes you made. But, apparently the brightness can be controlled from the command line using xrandr. I've never done it. I found that googling. There are other how-tos about using that command for that purpose.
If someone were good at scripting, they could write a script to get the current value, increment/decrement that value, and set it. In that way, the script could be assigned to a keyboard combination. Like Windows + q (and Windows + w) to increment & decrement. Pass the script a parm to tell it which way it's supposed to go.
I've never understood grub. I think it saves a copy somewhere. I don't know if the commonly-used "boot-repair" tool would get you back to before that change. (I'd wait for someone to suggest that before trying it.).
If someone were good at scripting, they could write a script to get the current value, increment/decrement that value, and set it. In that way, the script could be assigned to a keyboard combination. Like Windows + q (and Windows + w) to increment & decrement. Pass the script a parm to tell it which way it's supposed to go.
I've never understood grub. I think it saves a copy somewhere. I don't know if the commonly-used "boot-repair" tool would get you back to before that change. (I'd wait for someone to suggest that before trying it.).