vc_dispmanx_set_wl_buffer_in_use: Undefined symbol loading rpi-backend.so module.

[Paul]

Hi,

I have been trying to build the latest Weston on my Raspberry Pi.
In a recent patch there is a call to a new function 
'vc_dispmanx_set_wl_buffer_in_use'.
This is declared as a stub in 'rpi-bcm-stubs.h'.
I have updated my Raspberry Pi to the latest Kernel and Userland stuff 
but I cannot find this function in a header file and it does not seem to 
be exported by the VC libs.
Is the intention for the Raspberry Pi foundation / Broadcom to implement 
this function in dispmanx or is this an oversight?

Regards,
Paul.