setting dev.acpi_ibm.0.events at boot time

[Takashi Inoue]

> Thanks for the information. I'll try it from now.
> 
> I can change the brightness using sysctl by hand in x-term after login.
> However, /etc/sysctl.conf has no effect on ttyv8.
> Moreover, I see sometimes inconsistency between the value and actual 
> brightness, after several change of ttyv#.

I've tried xbacklight. It works perfectly.
No need to be root. It's great!
I'll not use lcd_brightness more.

T. Inoue