TMS320F280049: How to set the LIN length when two different lengths are received?

Hi,

PID 0x06 data length is 7 byte, 0xD8 is 1byte.

How to set the LIN length when two different lengths are received?

It can only receive 0xD8 when set length to 1. Or it can only receive 0x06 if set it to 7. 

Here is our code marked by blue. Thanks.