Comment 109 for bug 257827

On my Lenovo X301 (Gentoo kernel 2.6.38 w/ thinkpad_acpi, xfpm 1.0.10), I get the following behaviors:

1) 16 levels in text console using the brightness keys
2) 16 levels in the brightness panel applet using the scroll widget
3) 6 (=0th + (16-mod(16,3))/3) levels using the brightness keys in X

Now, if I set video.brightness_switch_enabled=0 in my kernel params:

1) No brightness adjustment in text console
2) Panel applet still gives 16 levels
3) The brightness keys give 9 levels (=0th + 16/2) in X

So before the backlight adjustment was getting tripled, now it is doubled. One was ACPI, another is xfpm, what is the third which is still active? Setting brightness_enable=0 for the thinkpad_acpi modules does not affect anything ...