sg_init_table(sg, 1);
                sg_dma_address(sg) = dma_map_single(adapter->dev,
                        ctl->skb->data, DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
-               err = dma_mapping_error(adapter->dev, sg_dma_address(sg));
-               if (unlikely(err)) {
+               if (dma_mapping_error(adapter->dev, sg_dma_address(sg))) {
+                       err = -ENOMEM;
                        sg_dma_address(sg) = 0;
                        goto out;
                }
                ctl->adesc = dmaengine_prep_slave_sg(ctl->chan,
                        sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
 
-               if (!ctl->adesc)
+               if (!ctl->adesc) {
+                       err = -ENOMEM;
                        goto out;
+               }
 
                ctl->adesc->callback_param = netdev;
                ctl->adesc->callback = ks8842_dma_rx_cb;
                goto out;
        }
 
-       return err;
+       return 0;
 out:
        if (sg_dma_address(sg))
                dma_unmap_single(adapter->dev, sg_dma_address(sg),