ethernet: micrel: fix some error codes

There were two issues here:
1) dma_mapping_error() return true/false but we want to return -ENOMEM
2) If dmaengine_prep_slave_sg() failed then "err" wasn't set but
   presumably that should be -ENOMEM as well.

I changed the success path to "return 0;" instead of "return ret;" for
clarity.

Fixes: 94fe8c683cea ('ks8842: Support DMA when accessed via timberdale')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/net/ethernet/micrel/ks8842.c b/drivers/net/ethernet/micrel/ks8842.c
index 09d2e16fd6b0..cb0102dd7f70 100644
--- a/drivers/net/ethernet/micrel/ks8842.c
+++ b/drivers/net/ethernet/micrel/ks8842.c
@@ -561,8 +561,8 @@ static int __ks8842_start_new_rx_dma(struct net_device *netdev)
                 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;
                 }
@@ -572,8 +572,10 @@ static int __ks8842_start_new_rx_dma(struct net_device *netdev)
                 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;
@@ -584,7 +586,7 @@ static int __ks8842_start_new_rx_dma(struct net_device *netdev)
                 goto out;
         }
 
-        return err;
+        return 0;
 out:
         if (sg_dma_address(sg))
                 dma_unmap_single(adapter->dev, sg_dma_address(sg),