Build error (2.5.52): undefined reference to `agp_generic_agp_3_0_enable'

Hi,

Compilation of 2.5.52bk6 fails due to the following error :

ld -m elf_i386 -e stext -T arch/i386/vmlinux.lds.s arch/i386/kernel/head.o
arch/i386/kernel/init_task.o  init/built-in.o --start-group  usr/built-in.o
arch/i386/kernel/built-in.o  arch/i386/mm/built-in.o
arch/i386/mach-generic/built-in.o  kernel/built-in.o  mm/built-in.o
fs/built-in.o  ipc/built-in.o  security/built-in.o  crypto/built-in.o
lib/lib.a  arch/i386/lib/lib.a  drivers/built-in.o  sound/built-in.o
arch/i386/pci/built-in.o  net/built-in.o --end-group  -o vmlinux
drivers/built-in.o: In function `via_kt400_enable':
drivers/built-in.o(.init.text+0x4e4f): undefined reference to
`agp_generic_agp_3_0_enable'

Concerning config options:

CONFIG_AGP=y
# CONFIG_AGP3 is not set
CONFIG_AGP_VIA=y

Best regards,
Axel Siebenwirth