[gentoo-user] Where does /sys/class/backlight/intel_backlight come from?

[Grant]

Does anyone know which kernel option would be responsible for
/sys/class/backlight/intel_backlight?  I've disabled some backlight
stuff in the kernel but the directory still appears.  I get screen
backlight control on my laptop if I do:

echo 0 > /sys/class/backlight/intel_backlight/brightness

but if xlockmore blanks my screen, I have to issue the above again
before screen backlight control works again.  I also have acpi_video0
in /sys/class/backlight and I think removing intel_backlight might fix
the problem.

I could try deleting the directory.  Is that safe?  Are the files and
folders in /sys generated dynamically at boot?

- Grant