CC3200AUDBOOST: dma interrupt fires only once

 I am trying to read a .wav file from sd card and play it using I2S on CC3200 audio booster in Energia. I have modified the Wifi audio example for this.

The dma is setup in ping pong mode and sd card loads data into the buffer but the tx dma interrupt fires only once in primary mode and once in alternate mode. I could not understand why its firing only once.

I have configured I2S in stereo mode with 16KHz  sampling frequency and 16 bit size.

This is my tx dma handler .

Thanks ,

Ram