st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
 dma_chan_disable:
        dma_release_channel(st->dma_st.dma_chan);
-       st->dma_st.dma_chan = 0;
+       st->dma_st.dma_chan = NULL;
 dma_exit:
        dev_info(&pdev->dev, "continuing without DMA support\n");
 }
        dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
                          st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
        dma_release_channel(st->dma_st.dma_chan);
-       st->dma_st.dma_chan = 0;
+       st->dma_st.dma_chan = NULL;
 
        dev_info(&pdev->dev, "continuing without DMA support\n");
 }