From: Andy Whitcroft When compiling 2.6.19-rc2-mm1 we get the following link failures: drivers/built-in.o(.init.text+0x3076): In function `toshiba_acpi_init': : undefined reference to `backlight_device_register' drivers/built-in.o(.exit.text+0x170): In function `toshiba_acpi_exit': : undefined reference to `backlight_device_unregister' When we build an ACPI module which provides backlight support we need to ensure that the backlight class device is selected. Signed-off-by: Andy Whitcroft Cc: Holger Macht Cc: "Brown, Len" Signed-off-by: Andrew Morton --- drivers/acpi/Kconfig | 2 +- 1 files changed, 1 insertion(+), 1 deletion(-) diff -puN drivers/acpi/Kconfig~add-support-for-the-generic-backlight-device-to-the-asus-acpi-driver-fix drivers/acpi/Kconfig --- a/drivers/acpi/Kconfig~add-support-for-the-generic-backlight-device-to-the-asus-acpi-driver-fix +++ a/drivers/acpi/Kconfig @@ -179,7 +179,7 @@ config ACPI_NUMA config ACPI_ASUS tristate "ASUS/Medion Laptop Extras" depends on X86 - select BACKLIGHT_DEVICE + select BACKLIGHT_CLASS_DEVICE ---help--- This driver provides support for extra features of ACPI-compatible ASUS laptops. As some of Medion laptops are made by ASUS, it may also _