I'm facing a puzzling issue on my laptop, an Asus EeePC 1015bx, which has an AMD C-60 APU and is running Gentoo.
Although the screen powersave functions are working in X11, the backlight does not switch off when I'm at a virtual terminal. Brightness controls are working. This behaviour occurs when using the open source radeon driver with kernel mode setting, but is also present when using fglrx with the VESA framebuffer driver for virtual terminals.
I've tried the various settings available with setterm, without any success. The screen blanks at the set time (goes to black on VESA framebuffer or to white on radeondrmfb), and if powerdown is explicitly set, it flickers after that amount of time, but the light stays on nonetheless. At the moment I can only manually switch off the backlight in sysfs using the eeepc-wmi interface in /sys/class/backlight. The radeon_bl0 interface in the same folder allows control of the brightness, but not of the backlight power.
Does anyone with a similar device have any idea on how to get the backlight to automatically switch off after a certain time without user input on the virtual terminal?