net: ethernet: ti: netcp_core: return error while dma channel open issue

Fix error path while dma open channel issue. Also, no need to check output
on NULL if it's never returned.
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/netcp_core.c

@@ -1353,9 +1353,10 @@ int netcp_txpipe_open(struct netcp_tx_pipe *tx_pipe)
 
 	tx_pipe->dma_channel = knav_dma_open_channel(dev,
 				tx_pipe->dma_chan_name, &config);
-	if (IS_ERR_OR_NULL(tx_pipe->dma_channel)) {
+	if (IS_ERR(tx_pipe->dma_channel)) {
 		dev_err(dev, "failed opening tx chan(%s)\n",
 			tx_pipe->dma_chan_name);
+		ret = PTR_ERR(tx_pipe->dma_channel);
 		goto err;
 	}
 
@@ -1673,9 +1674,10 @@ static int netcp_setup_navigator_resources(struct net_device *ndev)
 
 	netcp->rx_channel = knav_dma_open_channel(netcp->netcp_device->device,
 					netcp->dma_chan_name, &config);
-	if (IS_ERR_OR_NULL(netcp->rx_channel)) {
+	if (IS_ERR(netcp->rx_channel)) {
 		dev_err(netcp->ndev_dev, "failed opening rx chan(%s\n",
 			netcp->dma_chan_name);
+		ret = PTR_ERR(netcp->rx_channel);
 		goto fail;
 	}
 

drivers/soc/ti/knav_dma.c

@@ -413,7 +413,7 @@ static int of_channel_match_helper(struct device_node *np, const char *name,
  * @name:	slave channel name
  * @config:	dma configuration parameters
  *
- * Returns pointer to appropriate DMA channel on success or NULL.
+ * Returns pointer to appropriate DMA channel on success or error.
  */
 void *knav_dma_open_channel(struct device *dev, const char *name,
 					struct knav_dma_cfg *config)