Generic RNDIS: can't send data of more then MaxPktSize

Hi

I use USB module (for am1705) for mass storage device implementation. Now it works fine under CPU control (Ep1 - Rx, Ep2 - Tx). And I want to use DMA CPPI only for transferring data to HOST (for Ep2). So, I configured CPPI for work with Ep2: Generic RNDIS mode, one HPD for transferring buffer (65536 bytes), fifo size - 512 bytes, MaxPktSize -  512 bytes, GRNDISSIZE register – size of data in buffer.

When I need to transfer only 512 bytes CPPI works fine. But when it is required to transfer more than 512 bytes CPPI does nothing but Tx Completion Queue looks like all data was sent.

Could you please explain how to send more than 512 bytes of data in Generic RNDIS mode?

Thank you in advance.