Scatter Gather DMA C code from altera wiki ?

Hello

I used the sg dma example design from

"http://www.alterawiki.com/wiki/File:Sg-dma.zip"

I run that on cycloneV

the qsys connection are as the following

the design is waiting for and "blocked:" here

while(tx_done == 0) {}

what can I check to debug that ?

Thanks!