require help regarding HDLC-ETH bridging using kernel linux-2.4.20.

Having done the required patching to the kernel to upgrade the HDLC version 1.02 to 1.14, it should support HDLC to ethernet bridging but i get below error:

./sethdlc hdlc0 hdlc-eth nrz no-parity

hdlc0: Unable to set HDLC-ETH protocol information: Operation not supported.

Can someone help me in solving this error while configuring HDLC-ETH emulation.