net: dsa: exit probe if no switch were found

If no switch were found in dsa_setup_dst, return -ENODEV and
exit the dsa_probe cleanly.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index d5a162cda0878fe3b7041e9f017c8b39b615728f..adb5325f49348412efb50f0eeee5a5f0fa1e50ed 100644 (file)
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -837,10 +837,11 @@ static inline void dsa_of_remove(struct device *dev)
 }
 #endif
 
-static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
-                         struct device *parent, struct dsa_platform_data *pd)
+static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
+                        struct device *parent, struct dsa_platform_data *pd)
 {
        int i;
+       unsigned configured = 0;
 
        dst->pd = pd;
        dst->master_netdev = dev;
@@ -860,8 +861,16 @@ static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
                dst->ds[i] = ds;
                if (ds->drv->poll_link != NULL)
                        dst->link_poll_needed = 1;
+
+               ++configured;
        }
 
+       /*
+        * If no switch was found, exit cleanly
+        */
+       if (!configured)
+               return -EPROBE_DEFER;
+
        /*
         * If we use a tagging format that doesn't have an ethertype
         * field, make sure that all packets from this point on get
@@ -878,6 +887,8 @@ static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
                dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
                add_timer(&dst->link_poll_timer);
        }
+
+       return 0;
 }
 
 static int dsa_probe(struct platform_device *pdev)
@@ -927,7 +938,9 @@ static int dsa_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, dst);
 
-       dsa_setup_dst(dst, dev, &pdev->dev, pd);
+       ret = dsa_setup_dst(dst, dev, &pdev->dev, pd);
+       if (ret)
+               goto out;
 
        return 0;