Need help in enable configuration when compile Kernel module

[m silverstri]

I am using 3.10.x kernel tree. My kernel module needs config VIDEOBUF2.

That is defined in drivers/media/v4l2-core/Kconfig:

# Used by drivers that need Videobuf2 modules
config VIDEOBUF2_CORE
select DMA_SHARED_BUFFER
tristate

So I put 'CONFIG_VIDEOBUF2_CORE=y' in my Kernel config file and
compile. From the Kconfig it has CONFIG_VIDEOBUF2_CORE has no
dependency and I think adding CONFIG_VIDEOBUF2_CORE=y to my kernel
config should work. I am modify the right kernel config file since I
set other flags like CONFIG_VIDEO_DEV=y and that works.

The generated .config does not contain 'CONFIG_VIDEOBUF2_CORE=y'

and the compilation fails with  a bunch of

undefined reference to `vb2_buffer_done'
undefined reference to `vb2_buffer_done'
undefined reference to `vb2_buffer_done'
undefined reference to `vb2_buffer_done'

I really appreciate if someone can help me with this.

Thank you.