struct dmasg *sg;               /* large mode descriptor */
        unsigned int ctrl_num;  /* controller number */
        unsigned int irq;
-       irq_handler_t irq_callback;
        void *data;
        unsigned int dma_enable_flag;
        unsigned int loopback_flag;
 
 #endif
 
        dma_ch[channel].device_id = device_id;
-       dma_ch[channel].irq_callback = NULL;
+       dma_ch[channel].irq = 0;
 
        /* This is to be enabled by putting a restriction -
         * you have to request DMA, before doing any operations on
                               "Request irq in DMA engine failed.\n");
                        return -EPERM;
                }
-               dma_ch[channel].irq_callback = callback;
        }
        return 0;
 }
        disable_dma(channel);
        clear_dma_buffer(channel);
 
-       if (dma_ch[channel].irq_callback != NULL)
+       if (dma_ch[channel].irq)
                free_irq(dma_ch[channel].irq, dma_ch[channel].data);
 
        /* Clear the DMA Variable in the Channel */