acpi_backlight_video
if (acpi_video_get_backlight_type() != acpi_backlight_video)
if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video &&
return acpi_backlight_video;
acpi_backlight_dmi = acpi_backlight_video;
acpi_backlight_cmdline = acpi_backlight_video;