* event notify code.
* lcd_flag :
* 0. The system BIOS should automatically control the brightness level
- * of the LCD when the power changes from AC to DC
+ * of the LCD when:
+ * - the power changes from AC to DC (ACPI appendix B)
+ * - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
* 1. The system BIOS should NOT automatically control the brightness
- * level of the LCD when the power changes from AC to DC.
+ * level of the LCD when:
+ * - the power changes from AC to DC (ACPI appendix B)
+ * - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
* Return Value:
* -EINVAL wrong arg.
*/